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BIKE REPAIR MANUAL

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Page 1: Bicycle Repair Manual

BIKEREPAIR

MANUAL

Page 2: Bicycle Repair Manual
Page 3: Bicycle Repair Manual

BIKE

REPAIR

MANUALC H R I S S I D W E L L S

Page 4: Bicycle Repair Manual

ContentsIntroduction 7

GETTING TO KNOW YOUR BIKE 8

The basic bike 10

Anatomy of the bike 12

Bikes for general use 14

Specialist bikes 16

Setting up an adult’s bike 18

Setting up a child’s bike 20

CARING FOR YOUR BIKE 22

Tools 24

Workshop principles 26

Cleaning your bike 28

Lubricating your bike 30

Making routine safety checks 32

Servicing 34

Troubleshooting 36

Spotting danger signs 38

Preparing for wet weather 40

MAINTAINING YOUR TRANSMISSION 42

Cables and shifters

How they work 44

Drop handlebar gear cables 46

Straight handlebar gear cables 48

Front and rear mechs

How they work 50

Front mech 52

Rear mech 54

LONDON, NEW YORK, MUNICH,MELBOURNE, DELHI

Project Editor Richard GilbertSenior Art Editor Kevin Ryan

Art Editor Michael Duffy

Managing Editor Adèle HaywardManaging Art Editor Karen Self

Category Publisher Stephanie JacksonArt Director Peter Luff

DTP Designers Rajen Shah, Adam Shepherd

Production Controller Kevin Ward

Produced for Dorling Kindersley byEditor Pip Morgan

Designer Edward Kinsey

Photographer Gerard BrownTechnical Consultant Guy Andrews

First published in 2004 by DorlingKindersley Limited. Revised edition

published in 2005 by Dorling KindersleyLimited, 80 Strand, London WC2R 0RL

A Penguin Company

2 4 6 8 10 9 7 5 3 1

Copyright © 2004, 2005 DorlingKindersley Limited

Text copyright © 2004, 2005 Chris Sidwells

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording

or otherwise, without prior permission of the copyright owner.

A CIP catalogue record for this book is availablefrom the British Library.

ISBN 1 4053 0253 4

Reproduced by Colourscan in SingaporePrinted and bound by Star Standard in

Singapore

See our complete catalogue atwww.dk.com

Page 5: Bicycle Repair Manual

Hub gears

How they work 56

Hub gear I 58

Hub gear II 60

Chain, cassette, and chainset

How they work 62

Chains 64

Cassette and freewheel 66

Chainsets 68

Bottom brackets

How they work 70

Cartridge bottom bracket 72

Hollow-axle bottom bracket 74

BMX bottom bracket 76

Pedals

How they work 78

Pedal axle 80

Clipless pedals 82

Pedal cleats 84

STEERING AND WHEELS 86

Headsets

How they work 88

Threadless headset 90

Threaded headset 92

Handlebars

Straight handlebar 94

Drop handlebar 96

Hubs

How they work 98

Open-bearing hub 100

Cartridge hub 102

Wheels

Quick-release wheels 104

Puncture repair 106

Spokes and rims 108

ADJUSTING YOUR BRAKES 110

Rim brakes

How they work 112

Drop handlebar brake cable 114

Straight handlebar brake cable 116

Calliper brake 118

V-brake 120

Cantilever brake 122

Alternative brake designs 124

Hub-mounted brakes

How they work 126

Cable disc brake 128

Hydraulic disc brake I 130

Hydraulic disc brake II 132

Roller-brake cable 134

Coaster brake 136

TUNING YOUR SUSPENSION 138

Suspension forks

How they work 140

Front suspension 142

Coil/oil fork 144

Air/oil fork 146

Rear suspension

How it works 148

Rear suspension 150

Glossary 152Index 154Acknowledgments 160

Page 6: Bicycle Repair Manual
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A clean, well-maintained bike will work efficiently and safely, and add to your enjoyment of cycling by givingyou peace of mind.

Safety and efficiency are closelylinked. If your gears are not shiftingcorrectly, for instance, they will notonly affect your riding efficiency, butalso tempt you to look down at themwhile riding to see what is causing the problem. As a result, you mighttake your eyes off what is happeningon the road ahead and expose yourselfto the possibility of a collision. The Bike Repair Manual will help you avoid such problems by demonstratinghow to maintain your bike regularlyand correctly.

Understanding technologyModern bikes may seem complicatedand the technology that manufacturersuse may be more sophisticated thanever. However, cycle components work,as they have always done, according tological principles, so there is no reasonfor you to be daunted.

Before you begin to service a particular component of your bike, first become familiar with the part by turning to the relevant section.Knowing how a part works makes iteasier to maintain.

Above all, be confident and patientwith what you are doing. Even if youdo not think of yourself as mechanicallyminded, you may come to enjoy bikemaintenance after a time and will certainly enjoy the trouble-free cycling that rewards your efforts.

Collecting informationIf you buy a new bike, make sure thatyou keep the accompanying owner’smanual, so that you can refer to italongside this book. Do the same withany new equipment that you buy.

If your bike is not new, obtain amanual from a bike shop or the manufacturer’s web site. Manuals willhelp you to be aware of the particularmaintenance requirements of all thecomponents on your bike.

If you want to learn more aboutbike mechanics, there are many magazines available that contain tips on specific components. However,the large majority of people who aresimply interested in learning how tomaintain their bike will find everythingthey need to know in the pages of theBike Repair Manual.

Using this bookThe different maintenance requirementsof the most common types of bike arelisted at the beginning of the book.These requirements are covered in thestep-by-step pages that are specific to the components fitted to each typeof bike – for example, suspension forksfor mountain bikes.

You will also find a timetable forservicing the parts of your bike and a troubleshooting chart to help youidentify and solve problems. The bookhelps you to spot danger signs and tocarry out routine safety checks. Thesefeatures detail what you need to doand refer you to the relevant step-by-step sequences to explain how to do it.

Introduction

Page 8: Bicycle Repair Manual

1

Page 9: Bicycle Repair Manual

Understanding your bike

will make it easier to

maintain. Identify all

the different parts and

components to help

you see how they work

together as a whole.

GETTING TOKNO

W YO

UR B

IKE

Page 10: Bicycle Repair Manual

GETTING TO KNOW YOUR BIKE

Modern bikes, such as the hybrid bike (below),are designed to be light and user-friendly.The parts can be grouped into differentcategories, each performing a key functionin the overall operation of the bike.

The frame is the skeleton of the bike, onto which all components are fitted. The forkholds the front wheel, and connects to thehandlebar to allow the bike to be steered. The drivetrain is the system that transfers

Wheel (see pp.98–9, 104–9)The rim’s shape and high-techaluminium increases the wheel’sstrength. The wheel requiresfewer spokes, which reducesweight and air resistance.

Hybrid bike �Advances in technology haverefined the design and improvedthe performance of each categoryof bike part, producing a machinethat is easy to ride and maintain.

Mech (see pp.50–5)Mechs are designed tocope with the wide rangeof sprocket sizes requiredto climb and descend thesteepest hills.

Drivetrain (see pp.56–77)Stiff materials maximize the amount of power the drivetrain transfers to the rear wheel. A triple chainsetincreases gear range and a flexible chain allows quick,easy gear-shifts.

Pedal (see pp.78–85)Toe-clips and straps give increasedpower transfer to the pedals, andallow feet to be removed quickly.

Frame (see pp.12–13)Improved welding techniques allowthin-walled aluminium tubes toprovide a relatively cheap, light andresponsive frame. The thickness ofthe tube walls varies to cope withareas of increased stress.

the rider’s energy, via the pedals and cranks,to the rear wheel. It also contains a numberof cogs, known as chainrings and sprockets,which carry the chain.

The mechs (also known as derailleurs)change gear by moving the chain on to different chainrings and sprockets. They are controlled by the gear-shifters, which are mounted on the handlebar to allowquick and easy use by the rider. The brakes

The basic bike

10

Page 11: Bicycle Repair Manual

High-tech machine �Many years of design refinement have producedan adaptable hybrid bike, which combines technology from road and mountain bikes for use in an urban environment.

Gear-shifters (see pp.44–9)Ergonomically designed gear shifters were developed from mountain bikes, and giveeasy, precise gear-shifts.

Brake (see pp.110–37)The calliper brake was designedfor road racing bikes. Their dual-pivot action mimics the powerfulbrakes on mountain bikes, buttheir neat design improves thebike’s aerodynamics.

Fork (see pp.140–47)Forks are designed with varyingthickness in the tube wall. Tubesare thin in the middle, where notas much strength is needed, andthick at both ends. This reducesweight and absorbs road shock.

Tyre (see pp.106–7)Modern tyres are made fromrubber compounds that roll wellon the road, while adhering to it when cornering. They oftenhave puncture-resistant bands of material, such as Kevlar,beneath the tread.

are controlled by brake levers that are alsomounted on the handlebar, and use brakepads to press against the wheel’s rim to bringthe bike to a stop.

11

Page 12: Bicycle Repair Manual

Anatomy of the bikeUnderstanding how the parts on your bike fittogether will help you perform maintenancetasks successfully. Although your bike maydiffer from the modern mountain bike (right),all bikes fit together in a similar way. Forexample, the quick-release levers on thewheels below perform the same function as axle nuts on a bike with hub gears.

The main parts and their components, and where each part is attached to the bike,are shown on the mountain bike. Take thetime to study the illustration, since it will act as a useful reference to help you followthe steps later in the book.

Mountain bike �The mountain bike is a good example of howparts fit together since it has a similar frame,wheels, drivetrain, pedals, mechs, brakes,and gear-shifters to road and hybrid bikes.

Rear mech

Jockey wheel

Mech plate

Barrel adjuster

Cassette

Cassette body

Sprocket

Locknut

Saddle

Saddle cover

Saddle rails

Seat post

Saddle clamp

Frame

Seat tube

Seat stay

Chainstay

Down tube

Rear brake

Cable-guide tube

Braking surface

Brake pad

Brake arm

12

Rear hub

Rear drop-out

Hub

Quick-release

Bottom bracket

GETTING TO KNOW YOUR BIKE12

Page 13: Bicycle Repair Manual

THE ASSEMBLED BIKE

Bike parts are designed to bolt together in the same way to allow straightforwardmaintenance by following a few keyworkshop principles (see pp.26–7). Mostparts use Allen bolts, so for many tasks anAllen key multi-tool is all that is required.

Drivetrain

Right-hand crank

Chainring

Front mech

Chain

Tyres

Tyre bead

Valve

Tyre

Inner tube

Pedal

Pedal body

Foot retention mechanism

Pedal axle

Front wheel

Hub

Spoke

Rim

Bike controls

Gear-shifter

Handlebar

Grip

Brake lever

13Anatomy of the bike

Steering

Handlebar stem

Top cup and bearing

Spacer

Stem cap

Head tube

Top tube

Steerer tube

Bottom cup and bearing

Fork crown

Fork leg

Slider

13

Quick-release

Page 14: Bicycle Repair Manual

GETTING TO KNOW YOUR BIKE 14

You can buy a bike for almost every purposeimaginable but a simple utility, hybrid, orfolding bike will still increase your fitness,save you money on fares, and make nonegative impact on your environment.

As long as the bike is of good quality, you will only need to keep it clean and check it regularly for signs of wear. Hybridbikes, utility bikes, and folding bikes are alldependable machines that are suited tocommuting to work or school, day-to-daytransport needs, or simply a pleasurable ridein the park or even the countryside.

The hybrid bikeLightweight materials combined with roadbike performance and hardy mountain biketechnology make hybrid bikes perfect forbumpy urban roads. They are ideal forcommuting, family rides, fitness riding,touring, and carrying luggage.

The utility bikeUtility bikes are ideal for local commutingand short rides. They are equipped with fattyres that absorb road bumps but will dragon long journeys, making them hard work toride and uncomfortable.

The folding bikeIdeal for commuters, and for people withlittle space in which to store a standard bike,folding bikes can go anywhere, especially on public transport. The folded bike can be easily reassembled into a serviceablemachine without the use of tools.

Bikes for general use

Urban commutingWith its head-up, traffic-friendly riding positionand easy-to-operate gears, the lightweight hybridis ideal for urban commuting.

Page 15: Bicycle Repair Manual

Bikes for general use 15

UTILITY BIKE

FOLDING BIKE

• Regularly maintainand lubricate thederailleur gears (seepp.52–3, 54–5). • Check the gear cables for signs of wear (see p.39, pp.48–9).• Check the brakecables for signs of wear (see p.39,pp.116–17).• Check the tyres forsigns of wear (see p.39). • Regularly change thechain (see pp.64–5).

• Regularly lubricatethe hub gears (seepp.58–9, 60–1). • Regularly check thegear cables for signs ofwear (see p.39).• Regularly check thebrake control cables for signs of wear(pp.116–17).• Regularly check thebrake pads for signsof wear (see p.38). • Regularly clean andgrease the chain (seepp.28–9, 30–1).

• Regularly check andlubricate the pivots andthe locks that allow thebike to fold and unfold.• Regularly check hubgears, even though theyare shielded from theelements and so needvery little maintenance(see pp.58–9, 60–1) • Pay extra attention tothe outer control cables(see p.39, pp.48–9).

Tyre

Rearmech

Brake cable

Frontmech

Chain

Framehinge

Rear suspension

Large chainrings

Hub andderailleur gear

system

Hub gears

Brake lever

Folded bike

Unfoldedbike

ESSENTIAL MAINTENANCE CHECKLIST

Gear cable

Chainguard

Handlebar basket

Sprung saddle

HYBRID BIKE

Page 16: Bicycle Repair Manual

GETTING TO KNOW YOUR BIKE16

If you want to take up cycling as a sport or hobby, rather than simply as a means oftransport, look for a more specialized bike,such as a race level road bike, a mountainbike, or a BMX bike.

As bikes become more sophisticated theyneed more care. For example, lightweightparts wear quickly, so they must be keptscrupulously clean. Carbon wheel rimsrequire special brake pads that do not workwell on metal. Hydraulic disc brakes andsuspension systems need regular attention.

Do not let this put you off buying yourdream bike. Just as riding it will be a joy,maintaining it to exacting standards will be part of the whole cycling experience.

The road bikeLightweight materials and narrow tyres makeroad bikes good for fitness riding, day touring,and competitions. The aerodynamic positionafforded by a drop handlebar offers greatspeed. Road bikes are so light and have sucha range of gears that almost anyone, with alittle training, can tackle the great mountainpasses made famous by the Tour de France.

The mountain bikeFull-suspension mountain bikes allow you to break new ground and ride across ruggedterrain that was previously unthinkable andat speeds that were once unattainable.

The BMX bikeThese bikes are built for acceleration andagile bike handling. Like some of the veryfirst bikes, BMXs are made almost entirelyfrom steel because it transfers power in away that no other material can.

Specialist bikes

Road ridingThis road bike represents the ultimate in road bikedesign, and is the type of bike that professionalsuse in the Tour de France.

Page 17: Bicycle Repair Manual

Specialist bikes 17

MOUNTAIN BIKE

BMX BIKE

Calliper brake

20-speed gear-shift system

Road racetyre

Clipless pedal

Gyroheadset

Single gearing

Oppositetransmission

Aluminiumdrop handlebar

ESSENTIAL MAINTENANCE CHECKLIST

Rear derailleur

Rear V-brake Aluminium frameCross-countrytyre

Rearshock

Short-travelsuspension fork

ROAD BIKE

• Regularly clean andlubricate the bike (seepp.28–9, 30–1).• Make routine safetychecks (see pp.32–3).• Check the brakes (see pp.118–19). • Check the gears areworking perfectly (seepp.52–3, 54–5).• Where carbon-fibrecomponents fit insideother components,cover their joints withcopper-based anti-seize(see pp.30–1).

• Set up the suspensionsystem (see pp.142-43,150–51). • Regularly clean andlubricate the suspension(see pp.144–45, 146–47).• Inspect all pivots andseals regularly.• Check brake cablesand pads regularly (seepp.38–3, pp.116–17).• Replace the cassetteevery six months (seepp.66–7). • Service the headsetregularly (see pp.90–1,92–3).

• Regularly check thebottom bracket to seethat it is running free,but not loose (seepp.76–7). • Replace the pedals if their axles are bent(see pp.80–1).• Adjust the brakes toensure the minimum oftravel before the brakescome on, as the steelrims, though verystrong, do not makegood braking surfaces(see pp.124–25).

Carbon-fibrestraight handlebar

Aluminium/carbon-fibreframe

Stunt peg

Page 18: Bicycle Repair Manual

GETTING TO KNOW YOUR BIKE

Setting up anadult’s bikeIf the saddle’s height and angle are adjustedand the position of the brake levers on thehandlebar is set so that they are within easyreach, then riding will be more efficient andcomfortable. A novice cyclist should trysetting the saddle height a little lower atfirst, and work towards the ideal once he or she is used to riding.

Adjusting your ridingposition

Remove your shoes and sit on your bike,supporting yourself against a wall.

• Set your cranks so that the pedal furthest fromthe wall is at the low point of its revolution.

• Put the heel of your foot on the pedal. Your legshould be straight when you do this. Ask someoneto help you check.

Move your saddle back if the depressionon your leg is in front of the axle. If it is

behind, move it forwards.

• Undo the saddle clamp under the saddle. Onmodern bikes, you will need an Allen key; onolder bikes, use a spanner.

• Repeat Steps 4 and 5 until you are sure youhave the position right.

Place the widest part of your foot over thepedal axle. If your shoes have cleats, set

them up so that your foot can easily adopt thisposition (see pp.84–5 ).

• Set your cranks parallel to the floor. Thedepression on the side of your leading leg, justbehind the kneecap, should be directly over theaxle of the pedal. Ask your helper to check.

STEP LOCATOR

25

3

67

14

1

4 5

Toolbox

� Allen key multi-tool � Spanners � Screwdriver

The knee alignswith the axle

18

Page 19: Bicycle Repair Manual

Setting up an adult’s bike

Raise the saddle if your leg is not straightwhen your heel is on the pedal. Lower the

saddle if your heel does not reach the pedal.

• Undo the seat pin clamp bolt. Raise or lowerthe saddle, tighten up the bolt, and try again. Askyour helper to see if your leg is straight. Do notlean on the foot that you are testing.

To make absolutely sure the saddle heightis right for you, go for a ride with your

cycling shoes on and your feet in their normalposition on the pedals.

• Ask your helper to ride behind you and checkthat your hips are not rocking from side to side as you ride. If they are, the saddle is set too highand you need to repeat Steps 1 and 2.

Adjust the reach of the brake levers if youhave small hands and short fingers.

• Undo the brakes and screw in the adjuster oneach brake lever until you can reach the levereasily. Then reset the brakes.

• Set the brake levers at an angle to the handlebarso that you can pull them in line with your arm.

Make sure that the brake reach allowsyou to apply the brakes using the first

joints of your first two fingers, while holding the handlebar securely with your thumb andremaining fingers. You should be able to hook your fingers over the brake levers. If you have to stretch too far, you will be unable to apply the correct power.

19

2 3

6 7

Page 20: Bicycle Repair Manual

GETTING TO KNOW YOUR BIKE

Setting up achild’s bikeBefore a child starts riding a bike, adjust thesaddle and handlebar to suit his or her body.Set the saddle at its lowest point, as in Step 1.Buy the biggest bike possible at first, thenkeep adjusting it as the child grows taller.Children’s bikes are usually measured by wheelsize – from 30cm (12in) up to 60cm (24in).

Adjusting the position ofthe saddle

Set the saddle on your child’s bike at aheight that allows him or her to sit on it

and simultaneously to touch the ground with thefront part of each foot. This is the ideal set-up.

Raise or lower the bike’s handlebar byloosening the expander bolt that holds the

stem into the bike. This bolt is secured by eitheran Allen bolt or a hexagonal bolt, so use an Allenkey or a spanner to loosen it.

• Knock the bolt down with a plastic mallet tofree it up if you need to.

Grip the front wheel between your legs tosteady it and then pull the handlebar up or

push it down. Do not pull the handlebar higherthan the safety limit that is marked on the stem.Once the handlebar is at the right height, and thestem is lined up with the front wheel, tighten theexpander bolt.

20

1

21

STEP LOCATOR

123

12

3

Toolbox

� Allen key multi-tool � Spanners� Plastic mallet

Adjusting the height ofthe handlebar

Page 21: Bicycle Repair Manual

Setting up a child’s bike

Loosen the seat pin clamp – it either has aquick-release lever or a nut-and-bolt fixing

that requires a spanner. Either pull the saddle upor push it down to the required height.

Move the saddle forwards or backwards by loosening the nut that secures the seat

clamp. Tighten the nut again, but be sure that thesaddle is horizontal to the ground.

Adjust the saddleand handlebar still

further if you need to, sothat your child can sit inthe ideal riding position –neither too upright, nortoo stretched.

21

2 3

3

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2

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CARING FOR Your bike needs to be

kept clean and well

lubricated to avoid

mechanical problems.

Learning to make

cleaning, lubricating, and

checking a regular part

of your bike routine will

lengthen the life of your

bike and its components.

YOU

R BIKE

Page 24: Bicycle Repair Manual

If you are going to regularly maintain andrepair your bike, you will need to buy atoolkit or assemble your own. The toolsshown opposite will enable you to carry outall the essential repairs and to maintain yourbike at peak performance. Add other tools as the need arises when specific parts ofyour bike require maintenance or replacing.However, try to follow a few generalprinciples when using the tools.

When using tools on a bike, especiallylightweight bikes, you need a delicate touch.If you are used to working on cars, then useless force when dealing with your bike. Nutsand bolts only need to be tight; if you over-tighten them they will shear. If in doubt, buytorque gauges that accurately measure thecorrect level of tightness on a bike’s nuts and bolts. See the component manufacturers’instructions for recommended torquesettings. In fact, it is essential to keep all the instructions that come with your bike,tools, and any components you buy.

Buy the best-quality, precision-madetools. They will last for many years if youlook after them. Cheap tools will bend andbecome chipped, making it impossible tocarry out some maintenance jobs properly.They could even damage the componentsthat you work on.

Tools

Working with toolsWhen using your tools to maintain or repair your bike,give yourself plenty of roomand always work in a tidy, well-lit environment.

24 CARING FOR YOUR BIKE

Page 25: Bicycle Repair Manual

Tools 25

Workstand

Trackpump

Shock pump

Chainwhip

Crankpuller

Hollow-axlecup tool

Hollow-axle crank cap tool

Allen keymulti-tool

Allen keys2-10mm

Chaintool

Long-nosed pliers

(narrow)

Long-nosed pliers(wide)

Pegspanner

Spanner

Crank-bolt

remover

Cassette remover

SPECIALIST TOOLS

Some maintenance and replacement tasksrequire specialist tools that you will notuse very often. Other tools, such as thecable puller, are not essential but will make some jobs easier.

Cable puller

Bench vice

Spoke keysand spoke

ruler

Chain measuring

device

Essential toolkitsStart your toolkit with the twomulti-tools, the spanners to fitthe cones, long-nosed pliers,cable cutters, a pump, and aworkstand.

Plastic mallet

Cablecutters

Pumps and Workstand

Spanners and Allen Keys

Bottom Bracket Tools

Mallet

Transmission Tools

Pliers and Cable Cutters

Frame-fittingpump

Bottom-bracket remover

Spanner multi-tool

Spanners13-18mm

Page 26: Bicycle Repair Manual

CARING FOR YOUR BIKE

Workshop principles

Cutting cable outersUsing a spanner

Put the long axis ofan Allen key in theAllen bolt to make thekey easier to use, bothfor repeated turns andin places where spaceis tight or restricted,such as putting abottle cage on thedown tube.

Use the short axis of an Allen key tomake the final turnwhen tightening anAllen bolt – forexample, on achainring. You canalso use this techniqueto start undoing anAllen bolt.

Always use the correct size of spanner for thenut you are tightening or loosening. Hold thespanner firmly at the end to maximize leverage.Make sure that the jaws fully enclose the nut toprevent it from slipping.

26

Four key principles govern the work on yourbike. The most useful is tidiness – find a placefor each tool and return it there when youhave finished with it. Second, do not use toomuch force to tighten components – thenuts and bolts of lightweight parts can easily

Use long-nosed pliersto hold cables andkeep them undertension. Buy a smallpair with pointed jawsfor tight areas. Keepthe jaws clean andgrease-free. Lubricatethe pivot with light oiloccasionally.

Fix a cable tidy on toa brake cable to stopthe ends from fraying.Push the cable tidy onto the end of the cableand squeeze it flatwith your pliers. If youare gentle, you can usethe inside jaws of yourcable cutters.

Cut a brake cableouter between thespirals of the metaltube under the sheath.If the spirals becomecompressed, squeezethem with the insideof your cutter jawsuntil they are round.

Cut a gear cableouter through thewire under the sheath.If you need to, squeezethe wire with theinside of your cutterjaws until its cross-section is round again.

Using Allen keys Using pliers

shear. Third, remember the order in whichyou take components apart. Finally, keep all of your tools clean and dry.

The guidelines below provide you withgeneral principles for some of the mostcommon tools or operations in bike repair.

Page 27: Bicycle Repair Manual

Organizing a bike workshopRegularly maintaining your bike and carryingout essential repairs means that you can keepyour bike at peak performance. If you have thespace, the best place to do this is in a workshopthat is well organized and equipped with all thetools you need for your particular bike. Create aworkshop that is dry with plenty of light – andfollow the four key workshop principles.

Page 28: Bicycle Repair Manual

CARING FOR YOUR BIKE 28

Cleaning your bikeAlthough a bike is a very efficient anddurable machine, some of its more delicateparts are at the mercy of the elements. Gritand dirt, for example, stick to lubricants and act as a grinding agent. Clean the partsregularly to keep them running smoothlyand prevent them from wearing out.

While cleaning your bike, check all theparts and components for damage. With thewheels taken out, you can look at parts ofthe bike’s frame that are usually hidden and examine each component for signs ofdangerous wear (see pp.32–3 and pp.38–9).

The process of cleaning is straightforward.First remove old lubricants by applying adegreaser. Then wash the dirt off with water and detergent. Finally, rinse, dry, and lubricate the exposed moving parts.

Removing dirt and oil

Remove both wheels from the bike and putthe frame in a workstand or hang it up.

• Place a chain holder in the rear drop-out tokeep the chain tight while the rear wheel is out of the bike. This allows the chain to run freely sothat it can be cleaned thoroughly.

• Apply a degreaser to remove any old oil andgrit. Spray on to the chainset, front and rearmechs, and the chain, covering each link.

1

Spray the chainrings, chainset, and frontmech with more degreaser if there is still

stubborn oil and dirt (inset).

• Dip the sponge into hot, soapy water and wrapit around the chain. Turn the pedals so the chainruns through the sponge.

• Use the sponge to wash the rear mech (especiallyits jockey wheels), the front mech, and chainrings.

5Clean the rest of the wheel, including thetyres, with a bigger brush and soapy water.

• Work the bristles in between the spokes andaround the hub. Rinse with clean water and dryeverything with a cloth.

4

Cleaning equipment

� Plastic bucket � Sponges � Degreaser � Cloth� Hard-bristled brushes � Cassette scraper

Page 29: Bicycle Repair Manual

Cleaning your bike 29

Apply plenty of soapy waterto the rest of the bike with a

different sponge. Start at the topand work down.

• Use different-sized, hard-bristled brushes to work thewater into the places that are hard to reach.

• Rinse with clean water and dry the bike with a clean cloth.

• Use a sponge to worksoap into intricate parts,such as between the brakearms and the pads.

• Replace the wheels andsparingly apply a light oil to the chain and the moving parts of the front and rear mechs.

6

Use a hard-bristled brush on the cassetteso that the degreaser reaches into the

spaces between the sprockets. Allow a few minutes for the degreaser to work and wash off with soapy water.

3Use a cassette scraper to gouge out anydirt and debris that has accumulated

between the sprockets.

2

Page 30: Bicycle Repair Manual

Dribble some light oil inside the cableouters before you fit a new cable. This

makes sure that the cable runs smoothly inside.Poor gear-shifts are often due to cables runningdry inside their outers. The same is true of brakesthat are hard to apply and slow to return to theready-to-use position.

6

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STEP LOCATOR

CARING FOR YOUR BIKE

Lubricating your bikeRegular lubrication helps a bike to runsmoothly and prevents excessive wear andtear. Each time a part of the bike is lubricated,remember to remove the old oil and greasewith degreaser first (see pp.28–9). Applyingnew lubrication on top of old does not workbecause lubricants attract grit and dirt tothe bike and form a grinding paste that can cause damage.

The lubricants needed vary from lightspray oil (dry lube) and heavier oil (wet lube)to light grease manufactured specifically forbikes and anti-seize compounds.

Grease open bearingsafter regular cleaning

with a light grease specificallymade for bikes. Bottom bracketsand hubs need most attention,but headsets need regreasingless often. Riding regularly inthe rain shortens the intervalbetween lubrications.

Dribble light oil on to thepivots in the front and

rear mechs once a week. Thejockey wheels on the rear mechalso need some light oil wherethey rotate around the jockeywheel bolts.

• Make sure that you flush outany old oil with degreaser first.

Oil the chain after ridingin the wet, and clean, dry,

and lubricate when cleaningyour bike (see pp.28–9). Exceptin winter, or in bad conditions,use light oil from a spray can or bottle.

• Hold a cloth underneath thechain to catch any excess oil.

30

Applying oil and grease

1

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Page 31: Bicycle Repair Manual

Lubricating your bike

Spread anti-seize compoundon the seat pin and stem to

prevent the two components frombinding with the seat tube or steerertube. Although you can use grease in place of anti-seize, always use acopper-based anti-seize compoundfor lubricating components madewith carbon fibre.

31

6

Smear grease on all new cables and,occasionally, on old ones.

• Place a blob of grease on the nipple end of thecable, then pull the cable through your thumband forefinger before fitting it. Wear mechanic’sdisposable gloves.

2

Page 32: Bicycle Repair Manual

STEP LOCATOR

4

3

CARING FOR YOUR BIKE 32

Making routinesafety checksEvery week or so, check the bike frame forsigns of wear. Before going for a ride, runthrough a few checks to reduce the chancesof a mechanical failure: brakes that cease towork, a loose handlebar, a tyre blow-out, orslipping gears. The checks will help to avoidmany of the accidents caused by equipmentfailures. Safety checks help the managementof a bike, allowing the replacement of partsin good time or the completion of non-urgent maintenance work.

Making frame checks

Inspect the frame every week or so andlook for metal fatigue. Run a finger under

the down tube where it joins the head tube. Aripple in the tube’s surface could lead to a break.

• Check around the area where the chainstaybridge is brazed to the chainstays, particularly ona steel frame. Cracks may form in the metal herebecause of the heat of the brazing process.

1

Apply each brake fullyand push the bike forwards.

If the lever pulls to the barbefore the brake stops a wheelrotating, adjust the travel orreplace the pads.

• Apply the front brake. Tightenthe headset if you feel any playin the steerer assembly.

2 Lift the bike, slowly spinthe wheels, and check the

tyres for cuts, splits, or bulges. If you find a bulge, or are inany doubt, replace the tyre.Check the tyre pressure.

• Check that all quick-releaselevers are in the locked position,and wheel nuts are tight.

3Hold the front wheelfirmly between your legs

and try to turn the handlebarfrom one side to the other. Ifthere is any movement, checkthe stem and steerer bolts andtighten them if necessary.

• Try twisting the bar upwardsto look for rotational movement.

1

Making pre-ride checks

1 21 2

3

Page 33: Bicycle Repair Manual

Making routine safety checks 33

Monitor all the parts that are riveted toan aluminium frame, especially the cable

guides or the front mech hangers. The rivets formpotentially weak areas where stresses in the metalmay develop into cracks.

2

Run through the gears andmake sure that they are properly

adjusted. Gears that will not meshproperly after you change them can be distracting and, if you look down to see what is wrong,potentially dangerous. If thegears are correctly adjustedand the chain is still jumping,check for a stiff link.

4

Examine the slot under the seat-postbinder bolt since it can crack on any frame.

The slot breaks the seat tube’s integrity so thatstress can cause a split. To reduce the chances of this happening, always fit a seat post thatexactly matches the tube’s inside diameter.

3

Page 34: Bicycle Repair Manual

CARING FOR YOUR BIKE34

Servicing Schedule the work you need to carry out on your bike by developing a servicingtimetable. The timetable on the right provides a good template since it shows the tasks you should perform on your bikeand suggests when you should do them.

Your schedule depends on how much andwhere your bike is ridden. A heavily-used,off-road bike requires attention at muchshorter intervals, whereas a bike used forinfrequent, short road journeys will need less regular attention.

However, work carried out as part of a service schedule does not replace thesafety checks that must be carried outbefore every ride (see pp.32–3), or regularlylooking for danger signs (see pp.38–9). Youshould also check your bike and lubricate the transmission every time you clean it.

Chain for wear (see pp.64–5)Gear-shift performance (see pp.46–9, 52–5)Inner cables for fraying and outer cables for wear (see pp.46–9)Cranks and chainring bolts for tightness (see pp.68–9)

Oil chain (see pp.30–1)Oil jockey wheels (see pp.54-5)

Headset for looseness and ease of steering (see pp.90–3)Action of quick-release levers (see pp.104–5)Wheels for broken spokes and trueness (see pp.108–9)Handlebar and stem for cracks (see pp.94–7)

Inner cables for fraying and and outer cables for wear(see pp.114–17)Pads for wear and alignment (see pp.118–25, 128–29)Hydraulic hoses for wear, kinks, or leaks (see pp.130–31)Brake levers, arms, discs, and callipers for cracks (see pp.114–25, pp.128–33)Disc and calliper bolts for tightness (see pp.130–31)

Oil-exposed cables by wiping with wet lube on a rag

Fork and shock exterior surfaces for cracks (see pp.144–47, 150–51)Stanchions under shock boots, if fitted, for cracks(see pp.142–43)Top caps, crown bolts, and shaft bolts for tightness (see pp.140–41, 144–45, 146–47)

Teflon oil on fork stanchions and shock body, and on all seals (see pp.142–47, 150–51)

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EVERY WEEK

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Page 35: Bicycle Repair Manual

Servicing 35

Bottom bracket for smooth running, play, and bent axle (seepp.72–7)Pedals for play, and clipless pedals for play and release action(see pp.80–3)Rear mech pivots for play (see pp.54–5)Sprocket and chainring teeth for wear (see pp.66–9)

Oil mech pivots (see pp.30–1)Oil and grease inner and outer cables (see pp.30–1)Oil clipless pedal release mechanisms (see pp.40–1)

Chain on a heavily used bike (see pp.40–1, 64–5)

Hubs for play on axles, roughness, or tight spots (see pp.100–3)Rubber seals on hubs for splits (see pp.100–3)Covers, if fitted, on headsets (see pp.40–1)

Oil the seals on hubs (see pp.100–3)

Discs for wear and callipers for alignment (see pp.130–31)Coaster brake action and chain tension (see pp.136–37)

Grease inner cables and oil inside outer cables (see pp.30–1,114–17)

Brake pads of heavily used mountain bikes (see pp.120–23)

Fork and shock for play (see pp.142–47, 150–51)Fork stanchions to see if oil line visible (see pp.142–47)Fork and shock seals for cracks and slackness (see pp.142–47,150–51). Play, absence of oil lines, and cracked seals are all evidence ofworn seals, which should be replaced by a qualified technician.Fork and shock sag (see pp.142–43, 150–51)

Tip bike upside down and store overnight so oil canredistribute in fork

Freehub body and freewheel for play (see pp.66–7)Rear mech frame fixing bolt for play (see pp.54–5)Cleats for wear (see pp.84–5)Jockey wheels for wear (see pp.54–5)

Oil in hub gear, if equipped with oil port (see pp.58–9)Grease bearings in pedals (see pp.80–1)

Chain (see pp.64–5)Inner and outer cables (see pp.46–9)Sprockets on a heavily used bike (see pp.66–7)

Bearings in open-bearing hubs for wear (see pp.100–1)Bearings and bearing surfaces in headsets for wear (see pp.90–3)

Grease open-bearing hubs (see pp.100–1)Grease headsets (see pp.90–3)

Handlebar tape and grips (see pp.94–7)

Grease brake bosses (see pp.122–23)

Inner and outer cables (see pp.114–17)

Fork steerer for cracks, by removing the headset (see pp.90–3)

Fork oil (see pp.144–47)Seals on forks and shocks, as part of bi-annual service by qualified technician

EVERY MONTH EVERY SIX MONTHS

Page 36: Bicycle Repair Manual

CARING FOR YOUR BIKE

TroubleshootingThe symptoms of some of the things thatcan go wrong with your bike are listed inthis troubleshooting chart. It explains why a bike may be showing these symptoms andthen suggests a solution, referring you to the pages where you will find a detailedsequence of steps to guide you.

If you still find the problem difficult tosolve, consult the How They Work pages for the specific part you are working on, sothat you can understand it better. However,sometimes, the symptoms confronting youcan be due to a different malfunction to the one suggested in this chart. If afterconsulting the relevant pages in the bookyou still cannot solve the problem, ask theexperts at a good bike shop for help.

PROBLEM

When you apply the front brake and push the bike forwards, the headset moves forwards relative to the head tube.

You hear a sudden snapping noise come from a wheelwhile riding and/or the wheel goes out of true.

There is side-to-side play of a hub on its axle, or whenturning the axle in the hub you feel either a roughness or tight and loose spots.

When pedalling forwards, the cassette spins, but there isno drive to the bike. Alternatively, the cassette spinsbefore the drive is engaged or there is much side-to-sideplay in the cassette.

The brakes are hard to apply, and/or sluggish to release.

You have to pull the brake lever a long way before the brakes engage.

The two brake pads do not contact the braking surface atthe same time.

The brake pads contact the braking surface without pullingthe lever too far, but are ineffective at slowing the bike.

The fork regularly reaches the limit of its travel (bottoms out).

On steep, smooth descents, the rear wheel lifts under braking.

The front wheel judders up and down when cornering.

A rear air/oil shock regularly reaches the limit of its travel(bottoms out).

SOLVING COMMON PROBLEMS

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36

The chain will not shift on to a smaller sprocket or chainring.

The chain will not shift on to a larger sprocket or it shiftsbut does not run smoothly on it.

The chain shifts cleanly, but jumps on the sprockets whenpressure is applied to the pedals.

The chain rubs on the inner then the outer side of thefront mech cage. On a bike with a single chainring, thechain persistently falls off.

Page 37: Bicycle Repair Manual

Troubleshooting

CAUSE SOLUTION

Either grit has become lodged inside the cable outers or the cable lubrication has dried up.

The cable has stretched or the relevant mech ispoorly adjusted.

Either the chain has a stiff link; or the chain orsprockets, or both, are worn; or a chainring may be bent

The bottom bracket is worn or its axle may bebent.

Strip down the cables, flush the outers with degreaser, clean the inners with degreaser, lubricate, and reassemble.(See pp.30–1, 46–9.)

Unclamp the cable at the mech, pull through any slack, and re-tighten. Then set up the mech. (See pp.52–5.)

Check the chain for a stiff link and remove it if found. If no stifflink, replace the chain. If the problem persists, replace the sprockets.If the chainring is bent, replace it. (See pp.62–9.)

If the bottom bracket is a cartridge type, replace it. If it is a hollow-axle bottom bracket, replace the cup and bearing units. If it is a BMXbottom bracket, it may be possible to replace the bearings if they areworn, or to replace the axle if it is bent. (See pp.72–7.)

The headset is loose or worn.

A spoke may have broken.

The hub bearings are worn or, in the case of tightand loose spots, the axle is bent.

The freehub body is worn.

Strip and inspect the headset. Replace bearings if worn, regrease, andreassemble. Inspect the cups and races; if they are worn you shouldlet a good bike shop replace the whole headset. (See pp.90–3.)

Replace the spoke and true the wheel. (See pp.108–9.)

Replace the bearings or the axle. (See pp.100–3.)

Replace the freehub body. (See pp.100–1.)

Grit and dirt is inside the cable outers or the lubrication on the inner cables has dried.

The pads are wearing down or the cable has slippedthrough the clamp bolt.

Your brakes are not centred.

There is grease on the pads, foreign bodies embeddedin them, or they are wearing unevenly. You may evenneed a different compound of brake pad.

Strip down the cables, flush the outers, and clean the inner cables with degreaser, lubricate both, and reassemble. (See pp.30–1, 114–17.)

If the pads are not too worn, take up the extra travel by unclampingthe brakes, pulling the cable through the clamp, and tightening. Ifthe pads are worn, replace them. (See pp.112–25, 128–37.)

Follow the procedures for centring the type of brakes on your bike. (See pp.112–25, 128–37.)

Rub the pads with emery cloth. Remove foreign bodies with long-nosed pliers. Fit new pads if they are worn unevenly. Seek advice from a bike shop regarding different pad compounds. (See pp.112–25, 128–37.)

With air/oil forks, not enough air is in the system.With coil/oil forks, too light a spring is fitted.

The front of the bike is diving under brakingbecause the fork is not stiff enough.

The fork’s rebound is set too fast.

Insufficient air in the shock, or too much damping,means that the shock is not returning from each compression quickly enough.

Pump in more air. Replace springs with heavier duty springs. (See pp.142–45.)

Pump in air, or increase pre-load, according to the type of fork on your bike. (See pp.142–45.)

Use the relevant adjuster to reduce the speed of the fork’s rebound. (See pp.142–45.)

Set up the sag on the shock again. If the problem continues, use the damping adjustment to speed up the action of the shock. (See pp.150–51.)

37

Page 38: Bicycle Repair Manual

CARING FOR YOUR BIKE

Regularly check all the brake pads for unevenwear. This is a sign that they are not contactingthe braking surface evenly. The effectiveness ofyour brakes is compromised, because not all thepad’s surface is in use. Fit new pads and adjustyour brakes correctly (see pp.120–25).

Regularly check for worn or missing teeth on achainring or sprocket. The chain can jump whenyou apply pressure to the pedals, especially if youare out of the saddle, and you may be pitchedforwards and crash. Replace the chainring orsprocket as soon as you see this sign (see pp.66–9).

38

The more you ride your bike, the quicker thevarious moving parts, particularly tyres andbrake pads, will wear away. Replacing theparts as soon as they become worn not onlykeeps the bike running smoothly but alsoreduces the chances of an accident. You willsave money, too, since worn parts have theknock-on effect of wearing out other parts.

As you run through your safety checks (seepp.32–3), look for worn teeth on sprocketsand chainrings, worn brake pads, split orfrayed cables, worn wheel rims, bulging orsplit tyres, and worn tyre treads. If you spotany danger signs, take action as soon as you can. You must replace a damaged partbefore you next ride your bike.

Spotting danger signs

Sprockets and chainrings Brakes

Cables

Rims and tyres

SprocketsChainrings

Brakes

Worn teeth Worn brake pads

Checking for wearRegularly check the tyres,rims, brakes, chainrings,cables, and sprockets sothat you can spot signs ofwear as early as possible.

Page 39: Bicycle Repair Manual

Spotting danger signs

Check the whole circumference of both tyresfor bulges in the tread or the walls. Tyres withbulges or distortions are very likely to blow out if you ride on them. If you see any of these signs,replace the tyre (see pp.106–7).

Check all cables and cable outers for signs ofsplitting and fraying. Frayed inner cables can snap,leaving you without gears, which is inconvenient,or without brakes, which is dangerous. Change thecable before you ride again (see pp.46–9, 114–17).Worn or split outers reduce the effectiveness ofyour brakes and allow dirt to get in and clog thecables. Change the outer as soon as you can.

Look for evidence of deep scoring on the rimsof each of your bike’s wheels. Rim brakes willgradually wear out the rims, especially if you rideoff-road or in winter. Eventually, the rims will failand you could crash. Cracks around the nipples ofthe spokes where they join the rim are a dangersign, too. Replace the rim if you see these signs.

Check each tyre for splits or cuts in the tread orside walls. A large split means that the internalfabric of the tyre is damaged, so the tyre is likelyto blow out. Smaller splits and cuts will let sharpobjects penetrate the tyre, causing at least apuncture and possibly a rapid blow-out. Replacethe tyre if you see any splits or cuts (see pp.106–7).

39

Cables

Look closely at the tread of both tyres for signsof wear. If the tread is worn, the tyre has loststructural strength and can break down anddistort or bulge. The result can be a blow-outduring the course of a single ride. A tyre that hasbeen skidded and lost enough rubber to develop aflat spot can also be dangerous. Replace the tyreif you see either sign (see pp.106–7).

Rims and tyres

Split brake outer

Frayed gear outer

Split tyre Worn tread

Worn rim

Split or frayed cables

Bulging tyre

Page 40: Bicycle Repair Manual

CARING FOR YOUR BIKE

Preparing for wet weather

Keep water out of the point where the seat pinenters the frame. Mark this junction and removethe pin. Pull a piece of narrow road bike inner tubeover the frame. Insert the pin through the tube tothe mark and tie-wrap the tube to secure it.

40

These steps will help you to prepare a bikefor the rigours of winter, a particularly wetclimate, or if most of your riding is done off-road. The mud, sand, and water that yourwheels spray up into every part of the bikecombine to form a damaging, grinding paste.Salt, often used to treat roads where ice islikely to occur, will quickly corrode your

bike. Regular cleaning and lubricating helpswith protection, but try to stop the mud and salt from reaching the delicate parts of the bike in the first place. The overall aim when protecting a bike in winter is toprevent water reaching non-exposed partsand stopping water from washing off thelubricant on exposed parts.

Place a cover over the headset to provideprotection. You can fit a protector to the headsetwithout removing any components by simplyjoining up the velcro.

Shielding exposed componentsSealing the seat post collar Sealing the headset

Mech

Pedal

Headset

Seat postcollar

Mudguard

Chain

Protecting a bikeFit mudguards, insertseals, and lubricate the exposed parts toprotect a bike from wet conditions.

Page 41: Bicycle Repair Manual

Preparing for wet weather

Lubricate and clean your chain as often asyou do in summer and after every wet ride.Apply the same light lubricant that you use inthe summer and then apply a heavier oil, whichwill not wash off as easily. Only coat the rollersand insides of each link with heavier oil becauseit attracts more dirt.

41

Fitting mudguardsFasten a mudguard to the seat pin and you willblock much of the spray from the back wheel. For the front wheel, fit a guard that clips on tothe frame and is secured in place with tie-wraps.Full mudguards, which attach to the fork and reardrop-out, give almost full protection for on-roadbiking but get clogged up off-road.

Dribble oil on to the pivots around which thefront and rear mechs move. Use a heavier, wet oilrather than the oil you would normally applyduring the summer. Every time you dribble oil likethis, first flush out the old oil by dribbling somedegreaser on to the pivots and letting it sink infor a few minutes.

Apply heavier, wet oil to lubricate the retentionmechanism of clipless pedals after degreasing allthe moving parts. The heavier oil will not wash offas easily as dry oil. Regularly clean off old oil withdegreaser and apply new oil in order to preventthe accumulation of grit and the consequentincrease in pedal wear.

Cleaning and lubricating mechs

Cleaning and lubricatingpedals

Weatherproofing the transmissionCleaning and lubricating the chain

Page 42: Bicycle Repair Manual

3

Page 43: Bicycle Repair Manual

MAINTAINING YOURThe transmission is the

heart of your bike. Fine-

tune and regularly service

the system to ensure that

the gear-shifters, chain,

chainset, cassette, and

mechs work together in

perfect harmony.

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Page 44: Bicycle Repair Manual

MAINTAINING YOUR TRANSMISSION • CABLES AND SHIFTERS

CABLES AND SHIFTERSCables and shifters enable the rider to operate the gears. Cables are under constant tension and need to be replaced regularly and kept well lubricated. They must also be inspected oftenand replaced if they show signs of wear. Shifters requireonly occasional lubrication of their inner workings.

How they workAn inner cable connects the gear-shifter to the mech, and allows the rider to change gear. Gear-shifts made by a gear shifter causethe front mech to shift the chain from onechainring to another, or the rear mech to shift the chain from one sprocket toanother. Pulling the gear cable shifts thechain from a smaller to a larger chainring or sprocket; releasing the gear cableshifts the chain from a larger to a smaller chainring or sprocket. The left-hand shifter controls the frontmech; the right-handshifter controls the rear mech.

Controlling the gearsThe cables and shifterson a bike allow the riderto effortlessly control the gear system.

A clamp connects the cable tothe rear mech. When theshifter is pushed, the cablepulls the rear mech inwards,moving the chain from asmaller to a larger sprocket.When the shifter releases thecable tension, the springs onthe rear mech pull the jockeywheels, and the chain, back toa smaller sprocket.

REAR MECH CABLE

Cable clampAttaches the cable to the

rear mech

Rear mechMoves the chain from one

sprocket to another

44

Front mechMoves the chain

from one chainringto another

Page 45: Bicycle Repair Manual

How they work

Gear-shifters are often combinedwith the brake levers on thehandlebar. On this Shimano gear-shifter, the brake lever also actsas a shift lever. When the riderpushes the brake lever inwardswith the fingers, the controlcable attached to it is pulled anda ratchet mechanism is lifted. A click of this mechanism equalsone shift of the front or rearmech, which moves the chainacross the chainring or sprockets.The ratchet mechanism thenholds the cable in its new position. When the rider pushesthe inner shift lever inwards, the ratchet mechanism’s hold is released and so the shifter’spull on the cable ceases.

COMBINED BRAKE LEVER/GEAR SHIFTER ANATOMY

Gear-shifterPulls and releases the gear cable

RatchetmechanismHolds thecable

Brake leverPulls the cable

Inner shift leverReleases the cable

Cable outerCounteractsthe cable pull

Cable innerControls a mech

Lever hoodAttaches the levers to the handlebar

CableConnects

the shifterto the rear

mech

45

SHIFTING GEAR

In this Campagnoloshifter, the riderpushes the innershift lever to pullthe cable and movethe mech. Whenthe rider depressesa lever on the innerside of the leverhood, the cable isreleased and themech moves back.

Page 46: Bicycle Repair Manual

STEP LOCATOR

1

2

MAINTAINING YOUR TRANSMISSION • CABLES AND SHIFTERS46

Drop handlebargear cablesKeeping gear cables clean and lubricated,and replacing them if they fray, is veryimportant for smooth shifting. Change them as a matter of course at least once ayear, or more often if you are a heavy user.

Lubrication reduces the effects of frictionbetween the inner cable and the cable outer,and helps to keep out water and grit. If thegears become difficult to shift to a differentchainring or sprocket, the cable is probablydry and needs lubrication.

Friction increases with cable length. Cutcable outers as short as possible, but not soshort that they constrict the cable or restrictthe steering. If you are unsure how muchcable outer to cut, look at the arc of theouters on other bikes (see pp.10–17).

Replacing a Campagnolo gear cable

Replacing a Shimano gear cable

Remove the handlebar tape as the cableouter runs underneath it. You also need to

do this if you are replacing a brake cable.

• Carefully unwind the old tape from the centreof the handlebar to just below the shifter andleave it hanging while you carry out the work.

• Pull the rubber brake hood cover forwards tofree the tape beneath it. Pull the tape off slowly.

1

Place the gear-shifter in the smallestsprocket for the rear shifter and the

smallest chainring position for the front shifter.

• Pull back the brake lever and remove the oldcable from a hole on the outer side of the lever.

• Insert a new lubricated cable into the hole.

• Ease the cable through the hole and insert itinto the cable outer.

1

Toolbox

� Allen key multi-tool � Long-nosed pliers� Cable cutters

Parts of gear-shift units

Campagnolo Ergoshift

Shimano STI

Gear-shiftlevers

Brake/gear-shift lever

Inner shift lever

Insertion pointof gear cable(concealed bylever hood)

1 2 3

Lever hood

Rubber brakehood cover

Brake lever

Page 47: Bicycle Repair Manual

Drop handlebar gear cables 47

Put the rear shifter in the smallest sprocketand the front shifter in the smallest chainring.

Remove the old cable from under the hood cover.

• Grease the new cable and push it through thehole under the hood cover.

2

Pull the gear cablethrough pre-cut

lengths of cable outer with the long-nosed pliers.

• For the rear mech, thisusually requires one lengthfrom the shifter to thecable guide on the downtube, and another lengthfrom the guide on theright-hand chainstay to therear mech’s barrel adjuster.

• Place metal ferrules onthe cut end of each outerso that it fits snugly intothe cable guide.

• Finally, pull the cablethrough the barrel adjusterand cable-clamp bolt. Thentighten the bolt with theAllen key.

2

Dribble oil into a cable outer, which shouldbe cut to fit between the cable guide and

the component. If it is cut too short, it constricts;if it is too long, it increases friction (see pp.26–7).

• Ensure that metal ferrules are placed on theends of all the cable outers on your bike.

• Insert the cable into the cable outer. Keep thecable to the mech under tension as you clamp it.

3

Page 48: Bicycle Repair Manual

STEP LOCATOR

4

MAINTAINING YOUR TRANSMISSION • CABLES AND SHIFTERS48

Straight handlebargear cablesLooking after and replacing the gear cableson a mountain bike is very similar to a roadbike. However, mountain bikes are often subjected to harsher conditions than roadbikes, as they are often ridden through dirtand mud, so the cables must be replacedand lubricated more regularly.

Take special care if your mountain bikehas cable disc brakes because they havelonger lengths of cable outer and the cablesrequire lubricating more often.

Replacing a Rapidfire gear cable

Remove the old cable with long-nosed pliers and put the shifter in the smallest

sprocket or chainring position.

• Insert the end of the new, lubricated cable into the hole where the cable nipple sits insidethe shifter.

• Check the route of your existing cable and follow the route when fitting a new cable in Step 4.

1

Cut both the cable and cable outers withyour cable cutters to the same length as the

old ones you have removed. Make the outers longenough to allow the cable to travel freely inside.

• Dribble a drop of oil down each cable outer.

• Fit a ferrule to the end of each cable outer toensure that it fits tightly into the frame’s cableguides (see pp.26–7).

3

Toolbox

� 5mm Allen key � Long-nosed pliers� Cable cutters � Cable pullers

Parts of gear-shift units

Gear-shift levers

Handlebar clamp

Brake lever body

Shifter body

1 2 3

1 1

Gear indicator

Ring clamp

Barrel adjuster

Barrel adjuster

Shifter body

ShimanoRapidfire

ShimanoDual Control

SRAM Grip Shift

Cable port

Brake/gear-shift lever

Gear shift lever

Cable port

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Straight handlebar gear cables 49

Replacing a Grip Shift gear cable

Push the cable into the hole until its endshows through the barrel adjuster on the

outside of the shifter body.

• Thread the cable through the first length oflubricated cable outer.

2

Replacing a Dual Control gear cable

Thread the inner cable through eachlength of outer cable.

• For a rear mech, unscrew the barrel adjuster to about half its range and insert the inner cable.For a front mech, insert the cable into the clamp.

• Pull hard with your cable pullers and tightenthe cable clamp. Cut off any excess cable.

4 For the rear cable, put the shifter into thesmallest sprocket. For the front cable, put

the front shifter into the smallest chainring.

• Open the cable port to reveal the old cable insidethe shifter, and remove it with long-nosed pliers.

• Push the cable into the cable port until thecable nipple sits in the cradle inside the body.

• Follow Step 4 of Replacing a Rapidfire gear cable.

1

For the rear cable, put the shifter into thesmallest sprocket. For the front cable, put

the front shifter into the smallest chainring.

• Lift the cable port to reveal the old cable andremove it with long-nosed pliers.

• Grease the new cable and push it into the GripShift until the end protrudes from the shifter.

• Follow Step 4 of Replacing a Rapidfire gear cable.

1

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MAINTAINING YOUR TRANSMISSION • FRONT AND REAR MECHS

FRONT AND REAR MECHSThe two mechs move the chain smoothly between the sprockets andchainrings, but only if the travel of the mechs is set up correctly. Themech pivots and jockey wheels must be checked for wear and lubricated.The front mech must be properly aligned with the chainrings.

How they workThe front and rear mechs change the gears on a bike. Tochange up a gear, the shifter is used to pull on the cable,which causes the front mech to push the chain from asmaller to a larger chainring or the rear mech to pushthe chain from a smaller to a larger sprocket. To changedown a gear, the cable is released, causing the springs inboth mechs to move the chain to a smaller chainring orsprocket. Each mech moves around a pivot point. Highand low adjusting screws ensure that the mechs do notpush the chain beyond the largest chainring or sprocket,or pull it beyond the smallest. This range is called themech’s travel. Once its travel is set up, and provided thecable tension is sufficient, the mech will make a single,clean gear-shift for every click of the shifter.

Working with the shiftersThe front and rear mechs workin harmony with the shifters to provide easy, quick, and accurate gear-shifts wheneverthe rider needs them.

To change gear, two jockey wheels transfer the chain on to adifferent sprocket. They move in the same plane as the chainand are spring-loaded to preserve the tension in the chain.Two mech plates enable the jockey wheels to change gearupwards, while the plate spring enables the jockey wheels to change gear downwards.

REAR MECH ANATOMY

CablePushes andpulls the rear mech

Rear mechTransfers thechain fromone sprocketto another

Jockey wheel spring Preserves thetension in the chain

Jockey wheel Pulls and pushesthe chain

Jockey wheel cageHolds the jockeywheels

Cable clampAttaches the cableto the mech plates

CablePulls the mech plates

Mech plateTransfers cable pull to thejockey wheels

Plate springPulls the mech backas cable is released

High and lowadjustersLimit the travelof the mech

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When pulled, the cable moves the outer arm, which actslike a lever on a pivot point to push the front mech cageaway from the bike. This moves the chain from a smaller toa larger chainring. When the cable is released, a spring onthe mech’s inner arm pulls the cage back towards the bike.

FRONT MECH ANATOMY

REAR MECH IN USE

When the cable is pulled, it causes both the mech plates to swing inwards on four pivot points, causing the jockeywheels to guide the chain on to a larger sprocket. Whenthe cable is released, the plate spring moves the chain back to a smaller sprocket.

Front mechTransfers the

chain fromone chainring

to another

ChainringCarries

the chain

Small sprocket The chain isreturned to the smallest sprocket by the plate spring.

Large sprocket The chain ismoved to the largest sprocketby the pull of the cable.

51

Mechcage

Moves thechain

Pivot pointActs as a fulcrum

for the arm

Cable clampHolds the cable to the mech

Clamp boltFixes the mech

to the frame

High and low adjustersLimit the travel of the mech cage

Outer armActs as a lever

ChainringEngages

the chain

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STEP LOCATOR

MAINTAINING YOUR TRANSMISSION • FRONT AND REAR MECHS52

Front mechFront mechs (short for “mechanism”) shiftthe chain from one chainring to the next.There are two main kinds: braze-on mechs(below) are fixed by an Allen bolt to a lug, or protrusion, on the bike frame; band-onmechs are attached to a band that goesaround the frame and is part of the mech.

There are two important maintenancejobs for a front mech: setting it up after fitting a new control cable and adjusting itwhen it is not shifting properly. You shouldalso clean the mech regularly to prevent thebuild-up of dirt, which interferes with theway it works and will quickly wear it out.

For the mech to work perfectly, the loweredge of the mech cage’s outer side should be no higher than 2mm above the largestchainring. The cage’s outer side must also be parallel with the chainrings.

Correct shifts depend on the front mechtravelling a certain distance per shift. Highand low adjusting screws on the mech willcontrol this travel.

Adjusting a front mech

Shift the chain into the largest sprocketand the smallest chainring.

• Pull the front mech cage away from the frame.Note the distance by which the lower edge of itsouter side clears the largest chainring. This shouldbe 2mm. If it is more or less, undo the frame-fixing clamp and raise or lower the front mech.

• Line up the cage parallel with the chainringsand tighten the frame-fixing clamp.

1

Pull the gear cable through the cableclamp and tighten the cable-clamp bolt.

• Cut off any excess cable with your cable cutters and crimp on a cable tidy (see pp.26–7).

• Repeat Steps 2 and 3 if, after a couple of rides,the chain will not shift up to the next chainring,since cables can sometimes stretch slightly.

3

Toolbox

� Long-nosed pliers � 5mm Allen key � Screwdriver � Cable cutters

Parts of a braze-on front mech

High/lowadjusters

Front mechcage (inner side)

Front mech cage(outer side)

Cable-fixing clamp

1234

5

Frame-fixingclamp

Pivots

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Front mech 53

Undo the cable-fixing clamp until

the cable becomes free.

• Look for the low gearadjuster (usually marked“L”) and screw it in or outuntil the inner side of thefront mech cage is about2mm from the chain. Youhave now set the startingpoint of the mech’s travel.

• Take this opportunity toclean the guide in whichthe cable runs under thebottom-bracket shell. Usedegreaser, and then washand dry the whole area.

• Put a little dry lubricantin the guide.

2

Screw in the high adjuster (usually marked“H”) to bring the outer side of the front

mech cage to about 2mm from the chain.

• Unscrew the higher adjuster to allow moretravel if, when you shift on to the largest chainring, the chain does not move on to it.

• Check the action by shifting a few timesbetween all the chainrings.

5Shift the chain across until it is in thesmallest sprocket and the largest chainring.

• Repeat Steps 2 and 3 if the chain will not shifton to the largest chainring.

4

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STEP LOCATOR

MAINTAINING YOUR TRANSMISSION • FRONT AND REAR MECHS

Rear mechMost rear mechs are indexed, which meansthat for every click of the shifter, either upor down, the mech will shift the chain fromone sprocket to the next.

Occasionally, you may find that the chaindoes not quite move on to the next sprocketwhen you make a single shift, or else it skipsa sprocket in an overshift. In either case, therear mech needs adjusting. You will alsoneed to follow the steps in this sequencewhenever you fit a new cable (see pp.46–9).

To ensure that the rear mech worksfaultlessly, pay particular attention to itsjockey wheels because this is where oil anddirt can accumulate. Degrease and scrubthem every time you clean your bike (seepp.28–9). Whenever you lubricate the jockeywheels or the rear mech pivots, make surethat you wipe off any excess oil.

Adjusting a rear mech

Shift the chain on to the biggest chainringand smallest sprocket, then undo the

cable-fixing clamp so that the cable hangs free.

• Check the cable and fit a new one if it showsany sign of fraying (see p.39).

• Screw the barrel adjuster in or out, until it is athalf of its range.

1

Shift back to the smallest sprocket, thenshift upwards through each gear. If the rear

mech does not shift all the way on to the nextbiggest sprocket, screw out the barrel adjusteruntil it does. If the mech over-shifts and skips asprocket, screw in the barrel adjuster until it stops.

4

Toolbox

� Long-nosed pliers � Cable cutters� 5mm Allen key � Screwdriver

Parts of a rear mech

Jockey wheel

Barreladjuster

Mech pivot

Jockey cage

Cable-fixingclamp

1 2 3 4 5

54

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Rear mech

Use the high adjuster (usually marked “H”)to line up the jockey wheels with the

smallest sprocket.

• Once you have lined them up, rotate the pedalsforwards while adjusting the “H” adjuster until thechain runs smoothly.

• Pull the cable downwards through the cable-fixing clamp and re-clamp it.

2

Prevent the jockey wheelsfrom making contact with

the bigger sprockets by screwingin the adjuster that butts on tothe rear mech hanger on theframe drop-out. Remember tomake this adjustment if you fit a block or cassette with biggersprockets than usual.

5

Shift on to the smallest chainring andlargest sprocket.

• Push the rear mech with your fingers towardsthe spokes. If it moves beyond the largestsprocket, screw in the low adjuster (marked “L”)until the mech stops at the largest sprocket.

• Turn the pedals to see if the chain runssmoothly. If it does not, adjust the “L” in or out.

3

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MAINTAINING YOUR TRANSMISSION • HUB GEARS 56

HUB GEARSHub gears located inside the hub casing alter the speed at which the back wheel revolves. They require little routine maintenance and, since they are sealed, most hub-gear systems do not need to be lubricated regularly. The control cables must still be inspected regularly and replaced if they are worn.

How they workAll hub gears work according to the same basic principle. A system of internalcogs make the hub casing, and therefore the rear wheel, turn at a differentspeed to a single, external sprocket that is driven by the pedals via the chain.The sprocket is connected to the cogs by a driver unit and the cogs rotate the hub casing at different speeds. Spokes attach the casing to the rim,thereby revolving the rear wheel.

A shifter on the handlebar operates a mechanism attached to thehub. This mechanism causes various combinations of different-sizedcogs within the hub to engage with a ring gear, which drives thehub casing. Each combination gives a different gear ratio, and thenumber of gears depends on the number of cogs within the hub.

SHIMANO NEXUS HUB GEAR ANATOMY

Driver unitTransfers the sprocket’s drive andcauses the carrier unit to engagedifferent cogs with the ring gear

BearingsAid the rotation of the hub casing

Ring gearTurns the hub casing

Carrier unitCarries the

different-sized cogs

Cable and satelliteSide view of the hub

Hub casingTurns thewheel

To change gear, the rider activates the shifter topull the cable, which turns the satellite on thedrive side of the hub. This triggers a mechanismwithin the driver unit to move two carrier units

containing cogs. Different cogs are brought intocontact with the ring gears. When the cable isreleased, the spring-loaded carrier units movethe cogs back to a different combination.

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Protecting the gearsThe hub gear mechanism is fullyenclosed to protect it from damage, dirt, and water.

Hub gear unitContains the cogs thatallow gear changes

57

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STEP LOCATOR

24

MAINTAINING YOUR TRANSMISSION • HUB GEARS

Hub gear IIf the cable to your hub gear breaks or frays,you will need to replace it. Before making astart, first identify the hub gear units onyour bike from the manufacturer’s name.This is usually stamped on the hub and thenumber of gears is indicated on the shifter.

The hub-gear model illustrated in thesteps of this sequence is the Shimano Nexus7-speed gear, which is operated by a twistgrip shifter. Alternatively, bikes may beequipped with SRAM hub gears, as well asthose made by other manufacturers, that are operated by thumbshifters.

Some older bikes have Sturmey Archer 3-speed gears. Although they all work on thesame principle, the methods used to changea cable are subtly different. Try to find themanufacturer’s instructions for the gearfitted to your bike – ask at bike shops orsearch the internet.

Replacing a hub-gear cable

Put the shifter into first gear. At thispoint, there is no tension on the cable, so

it is the starting point for fitting a new cable. If the cable is broken, the hub gear will haveautomatically returned to first gear, so move the shifter there to line up the system.

1

Insert the cable through the chainstaycable guide and make sure that the outer

is well-seated into the guide.

• Pull the cable tight and tighten the clamp bolt on to it at exactly the distance you measured from the cable guide in Step 2.

• Now push the clamp bolt back into the placewhere it sits on the gear satellite (inset).

4

Toolbox

� Spanners to fit wheel axle nuts and cable-clampbolt � Flat-bladed screwdriver

Parts of a hub gear

Cable route

Lockring

Position of red dots(underneath)

Seat for cable-retaining bolt Right-hand axle nut

135

58

Gear satellite

Page 59: Bicycle Repair Manual

Hub gear I

Remove the rear wheel (see pp.136–37) andpush the wheel forwards out of the drop-out.

• Use a flat screwdriver to lever out the cable-clamp bolt from the position in which it sits onthe gear satellite.

• Pull on the clamp bolt and measure the length ofthe cable between it and the chainstay cable guide.Undo the clamp to remove it from the old cable.

2

Return the wheel to the bikeby placing the axle in the rear

drop-outs and pulling backwards onthe wheel so that there is tension onthe chain. Do not pull so hard thatthe chain becomes tight.

• Ensure that the wheel is straightbetween the chainstays and tighten

the axle nuts. There should beabout 6mm (1⁄4in) of verticalplay in the chain.

• Run through the gears, shiftby shift. If there is a problem, the hub gear may need adjusting(see pp.60–1).

5

Remove the cable port on the plastic partof the shifter, where the pointer indicates

which gear the system is in.

• Take the old cable out of the shifter by pushingit from behind, or pull it out by its nipple.

• Insert the greased new cable into the shifter.Dribble a little oil inside the outer and then pushthe new cable through the outer.

3

59

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STEP LOCATOR

235

MAINTAINING YOUR TRANSMISSION • HUB GEARS

Hub gear IIOccasionally, you might be unable to engagea particular gear because dirt has interferedwith the gear satellite’s action. You will needto remove the satellite to clean it and thismeans removing the rear wheel.

On other occasions, you might find thatthe shift has lost some of its smoothness. Inthis case, the cable has probably stretched sothat the shifter is out of phase with the gearmechanism. To remedy this problem, use thebarrel adjuster on the shifter to take up anyslack in the cable.

Every time the wheel is removed and putback on to your bike, run through the gearsand check that they are shifting correctly. If they are not, follow the last two steps ofthis sequence in order to make sure that thegears are running smoothly.

Finally, the hub-gear system has clearmarkings – look for the red dots and theyellow dots and triangles – to help you toset up the gears.

If a bike is fitted with a Sturmey Archer3-speed hub gear, it may occasionally shiftto second gear, but without any drive. Whenthis happens, put the shifter into the thirdgear position and look at the cable where itruns along the chainstay. The cable will beslack so that it sags. Undo the cable-clampbolt near to the hub-gear unit and pull thecable through the clamp until it runs in astraight line. Re-clamp the bolt and thegears will shift perfectly.

Adjusting your hub-gearassembly

Remove the rear wheel by undoing andremoving both its axle bolts (see pp.136-37).

The satellite is locked on to the hub by a lockring.Turn the lockring by hand until its yellow dot linesup with the one on the satellite.

• Lift off the lockring to free the satellite.

1

Put the satellite back on to the wheel.Line up its triangles with those on the axle.

• Press the satellite home on to the hub.

• Replace the lockring, pushing it on to thesatellite so that its yellow dot lines up with theyellow dot on the satellite.

• Turn the lockring so that the dots areseparated. The satellite is now locked in place.

3

Toolbox

� Spanners to fit wheel axle nuts

41

60

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Hub gear II

Lift the satellite fromthe hub body, noting

the relative positions of thetwo yellow triangles that aremarked on it.

• Note the position of twomore yellow triangles on thebare axle that is left insidethe wheel.

• Flush out the freed gearsatellite with degreaser. Letthis drain out and spray lightoil into the satellite.

2

Shift through the gears until the shifter is in fourth gear.

• Use the barrel adjuster on the shifter to fine-tune the gear adjustment. Tilt the bike sothat you can see the underside of the hub gear.

4 Look for the two red dots on the gearmechanism. One is marked on the satellite

and one on the lockring. Both dots are marked onthe underside of the gear where the cable runs. In fourth gear, these two dots should line up. Ifthey do not, screw the barrel adjuster in or outuntil the dots line up. When they do line up, allthe gear-shifts will be perfect.

5

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MAINTAINING YOUR TRANSMISSION • CHAIN, CASSETTE, AND CHAINSET

CHAIN, CASSETTE, AND CHAINSETWith every turn of the pedals the chain, cassette, and chainset areput under strain. The parts are in continual contact, and the motionof pedalling inevitably leads to wear. No matter how well you lookafter each part, they will eventually need removing and replacing.

How they workThe chain, cassette, and chainset combine toform the heart of the transmission, the partof the bike through which a rider’s pedalpower is transferred into forward motion.The pedals drive the chainset and, via thechain, turn a sprocket attached to the hub of the rear wheel, which in turn rotates the wheel.

Bikes with derailleur gears use mechs to shift the chain on to different-sizedsprockets and chainrings, which make up thecassette and chainset. Each combination ofchainring and sprocket provides a differentgear ratio, giving up to 27 different gearsthat can be used to tackle anything fromsteep climbs to gentle flats.

The cassette transfers the motion of the chainto the wheel. It consists of sprockets thatslide on to the cassette body, which is boltedon to the hub. The cassette body houses thefreewheel, which allows the wheel to turnwhen the cassette is stationary.

SprocketsDriven by the chain

ChainFeeds through jockey wheels

EXPLODED CASSETTE

Rear mechShifts the chain across the sprockets

Quick-release leverLocks wheel into

place

Cassette bodyContains the freewheel

Hub flangeSpokes

connect hubto wheel rim

ProfileSecures sprocketsto cassette body

SprocketSlides on to cassettebody

Spacer

LockringHolds sprocketson the body

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How they work

ChainringCarries the

chain around the chainset

Chain Transmits

power fromthe chainset

PedalTransmits

energy to thechainset

ChainsetPowered by

pedalling

Lightweight componentsThe chain, cassette, and chainset are lightweightitems that use the latest design and constructiontechniques to maximize strength and durabilitywhile maintaining an aerodynamic profile.

CHAIN ANATOMY

Rear wheelDriven by the sprockets

Inner linkRotates around the barrel

BarrelSits between teeth ofchainrings and sprockets

Outer linkShaped to allowquick gear shifts

Joining pinConnects inner and outer links

The chain is the key to transmitting pedal power into forward motion.

To transfer power efficiently thechain must be strong, but flexibleenough to fit securely around theteeth of the chainrings and sprockets. To achieve this, a seriesof links articulate around joiningpins, which are surrounded byrevolving metal barrels.

63

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STEP LOCATOR

12

MAINTAINING YOUR TRANSMISSION • CHAIN, CASSETTE, AND CHAINSET

ChainsReplacing a chain is a regular maintenancetask. All chains eventually wear out, even if you clean and lubricate them properly. A worn chain, as well as being inefficient,will quickly wear out other transmissionparts, and so prove expensive.

To determine how much a chain hasbecome worn, either use a specialist gaugefrom a bike shop or measure the length of24 links. If the length is greater than 300mm(12in), the chain is worn.

New chains on derailleur gear systems are linked with a joining pin that comes withthe chain. You will need a link extractor toolto make this join. The thicker chains of hubgears, BMX bikes, and some fixed-gear bikesare joined by split links.

Replacing a derailleur chain

Shift on to the smallest chainring andsprocket so that the chain is slack.

• Place a link in the link extractor and push outthe pin until the chain breaks.

• Remove the old chain with the link extractor.

1

Remove the excess links from the oppositeend to the one on which there is a joining

link. Leave an inner link so that the two ends canbe joined together.

• Join the chain by pushing the pin of the joininglink through the opposite inner link with theextractor tool.

3

Toolbox

� Chain link extractor � Long-nosed pliers

Parts of a split-link and a Shimano chain

Split-link pins

Groove

Outer plate

Split pin

Shimanochain

Split-linkchain

Innerlinks

1 2 3 4

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Chains

Joining a split-link chain

Thread a new chain through the jockeywheels and around the biggest chainring

and smallest sprocket.

• Pull the ends of the chain together so thatthere is a little tension in the jockey wheels. This establishes the length of chain you need.

2 Join the chain by pressing the side of thesplit link with the pins fixed in its plate

through the two inner-link ends of the chain.

• Press the other plate on to the pins that arenow sticking through the inner links.

1

Push the split pin into the grooves of thesplit-link pins. These are sticking through

the outer plate that you have just fitted. The splitpin’s open end should face the rear of the bike.

• Fix the split pin in place by pushing it homewith long-nosed pliers until you feel it click.

2Loosen any stiff links that occur when thechain links are compressed during Step 3.

• Flex the stiff links with a little sidewayspressure until they become loose (inset).

• Remove the protruding part of the pin afterjoining a Shimano chain, as these have an extra-long joining pin.

• Break off the excess with long-nosed pliers.

4

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STEP LOCATOR

1

3

2

MAINTAINING YOUR TRANSMISSION • CHAIN, CASSETTE, AND CHAINSET

Cassette and freewheel The cassette and freewheel allow the rearwheel to rotate while the pedals remainstationary. Their internal mechanisms – thefreehub body of a cassette and the block in a freewheel – will eventually wear out andneed replacing. The sprockets on both canalso wear. These parts will also need to beremoved whenever you replace a brokenspoke on the drive side of the rear wheel.

The tools for removing a freewheel and acassette depend on the manufacturer of thepart that is fitted to the bike. Usually, themanufacturer’s name is stamped on thecomponent. However, if you are in any doubtabout which tool you need, take the wheelto the shop when buying a remover tool.

Removing a cassette

Removing a freewheel block

Remove the quick-release skewer fromthe rear wheel.

• Insert the cassette remover into the teeth ofthe lockring at the centre of the cassette.

• Replace the quick-release skewer to secure thecassette remover.

1

Remove the quick-release skewer andinsert the block remover into the teeth at

the block’s centre.

• Lock the block remover in place by replacingthe quick-release skewer.

1

Toolbox

� Spanners � Cassette remover � Chain whip � Block remover � Grease

Parts of a freewheel and a cassette

Sprockets

Inner sideridges ofcassette

Lockring

Sprocket

Freewheel mechanism

Cassette

Freewheel

1 2 3

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Cassette and freewheel

Wrap the chain whip around a sprocket,and place the spanner on the remover.

• Press downwards on both tools. This holds thecassette, while the remover unlocks the lockring.

• Remove the quick-release skewer once thelockring starts turning.

• Continue to unscrew the lockring with thecassette remover.

2

Check the integral freewheel mechanism,which is independent of the hub. Replace it

with a new block if it is worn.

• Coat the threads of the hub with grease, thenscrew the block on by hand.

• Lock the block in place by tightening it withthe spanner and the block remover.

3Put the spanner on the flats of the blockremover and turn anticlockwise.

• As the block begins to move, remove the quick-release skewer and continue turning untilthe block comes off.

2

Take off the smallest sprocket after you have removed the lockring. On many

cassettes, the remaining sprockets come off in one piece. If they do not, you must put individualsprockets back in a certain way. Failure to do so will affect the precision of gear shifts. Usually,the sprockets are marked, so that lining up thesemarks ensures the correct sprocket orientation.

3

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STEP LOCATOR

1

5

234

MAINTAINING YOUR TRANSMISSION • CHAIN, CASSETTE, AND CHAINSET68

ChainsetsRemoving a chainset is a useful skill to havebecause it will allow you to replace an oldcrank, clean or replace a worn chainring, orwork on the bottom bracket.

Chainsets are attached in one of fourways. Those held in place by a hexagonalbolt can be removed with a chainset socketspanner (see Step 1). Chainsets with a self-removing Allen bolt can be detached withan 8mm Allen key (see Step 2). Versions witha standard Allen bolt can be detached withthe relevant Allen key (see Step 3). Those on a hollow-axle bottom bracket can beremoved by reversing the steps on pp.74–5.

When refitting a chainset, keep grease oroil from touching the axle. The chainset mustbe dry when fitted to the axle or it will workloose. After refitting, go for a short ride andthen try the axle bolt again. If it is slightlyloose, you should tighten it.

Removing a chainset

Detach a hexagonal chainset bolt fromthe axle with a chainset socket spanner.

Normal socket spanners are often too thick to fit into the space where the bolt is located.

• Steady the crank with your free hand to giveyou something to push against. Work from belowthe chainset so that if your hand or the spannerslips, the chainring teeth will not injure you.

• To remove the chainset, go to Step 4.

1

Use a crank extractor to remove thechainset if it is not the self-removing type.

Make sure that the washer beneath the bolt hasalso been removed.

• Carefully screw the extractor into the delicatethreads at the centre of the chainset. When theextractor is fully in, turn its handle clockwise topull off the chainset.

4

Toolbox

� Crank extractor � 5mm Allen key � 8mm Allen key or chainset socket spanner� Chainring bolt peg spanner

Parts of a chainset

Right-handcrank

Chainring bolt

Chainrings

Spider

Page 69: Bicycle Repair Manual

Chainsets 69

Use a long-handled Allen key if there isan Allen bolt holding the chainset on your

bike. Usually, an 8mm key is the size required.

• Work from below the chainset so that if youslip the chainring teeth will not injure you.

• To remove the chainset, go to Step 4.

3Unscrew a self-removing Allen bolt withan 8mm Allen key. These kinds of bolt

extract the chainset as you unscrew them.

• Steady the crank with your free hand to giveyou something to push against. Work from belowthe chainset so that if your hand or the spannerslips, the chainring teeth will not injure you.

• To remove the chainring, go to Step 5.

2

Remove the chainringwith a 5mm Allen key

on one side and a chainringbolt peg spanner to hold the bolt on the other. Youcan do this without takingthe chainset off the axle, butyou must remove it if you areworking on the inner rings ofsome triple chainsets.

• Cure a creaking noise fromthe chainset by puttinggrease on the threads of thechainring bolts before youreassemble the chainset.Standard chainring bolts are made from steel. Be especially careful not toover-tighten aluminium or titanium bolts.

5

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MAINTAINING YOUR TRANSMISSION • BOTTOM BRACKETS

BOTTOM BRACKETS

How they workThe bottom bracket joins the crank of eachpedal with an axle, which rotates in the bike’sframe. Each type of bracket consists of an axle,two bearings, and two threaded cups (called eitherthe free cup and fixed cup, or the non-drive anddrive-side cup). With the cartridge type, both cranks boltonto the axle, but with the hollow-axle type, the drive-side crank is fixed to the axle and only the non-drive sidecrank can be bolted on. A third type of bottom bracket,the BMX bracket, has a threaded axle – the bracket isheld in place by a locknut that screws on to the threadon the non-drive side of the axle.

Each of the cartridge bearingsis composed of ball-bearings,which are sandwiched between an inner and outer race by plastic seals. The cartridge bearings are located close to each end of the bottom-bracket axle. A tubular sleeve fits overthe two bearings, fillingthe space between them. The fixed and free cups fit over this sleeve to create a totally sealed unit.

70

CARTRIDGE-BEARING BOTTOM BRACKET ANATOMY

AxleConnects thecranks androtates inthe bearings

Free cupScrews intothe bike’sframe

CrankTurns the axle

Fixed cupHolds the bottom

bracket in place

Outer raceHouses the bearings

Ball-bearingSupports the axle

Providing strengthThe axle and bearings of the bottom bracket need to be both strong and reliable enough to bear the weight and power of the rider.

There are two main types of bottom bracket: cartridge-bearingand hollow-axle. Both use sealed bearings, which can wearout over time. If this happens on the cartridge version,replace the whole unit, but on a hollow-axle typeyou only need to replace the bearings.

Page 71: Bicycle Repair Manual

How they work

The drive-side crank ispermanently fixed to the axle,which passes through bothcups. The non-drive sidecrank slides onto the axleand is secured by twopinch bolts. The crankcap bolt inserts into theend of the axle to holdthe crank against thebearing, ensuring thatthere is no play, ratherlike the stem cap bolton a threadlessheadset (p.90).

CrankTurns the axle

71

HOLLOW-AXLE BOTTOM BRACKET ANATOMY

Ball-bearingLets the axle turn

CupHolds bearings in the frame

CrankTurns the axle

CupHolds the bearings

in place in the frame

AxleConnects the crankstogether and rotates

in the bearings

Pinch boltsHold crank in place onthe axle

Crank cap boltPresses crankagainst bearings

Cartridge-bearingbottom bracketAllows the smoothrotation of the axle

Page 72: Bicycle Repair Manual

MAINTAINING YOUR TRANSMISSION • BOTTOM BRACKETS

Cartridge bottom bracketCartridge bottom brackets require no routinemaintenance. Their bearings are sealed fromthe elements – even from the water you usefor hosing or pressure-washing your bike,provided that you turn the pedals forwardsduring the wash.

When the bearings do eventually wearout you will have to replace the whole unit.The remover tools for this job are specific toeach particular bottom bracket, so checkwhich make is fitted to your bike beforebuying the tools.

If you are planning a replacement, thereare three types of bottom bracket axle tochoose: square-tapered, Shimano Octalink,and Isis. The type used in the steps in thissequence is square-tapered; the type shownbelow is Octalink.

Finally, if you are having any problemsinstalling a bottom bracket on your bike, ask the experts at a bike shop to help you.

Installing a cartridge bottom bracket

Put the bike on a workstand and removethe chainset (see pp.68–9).

• Use a pair of callipers to measure the length of the old axle before you remove the bottombracket, so that you can be sure the replacementhas an axle of the same length. You need to dothis because different chainsets are designed towork with different axle lengths.

1

Grease the threads of each side of the new bottom bracket for easier fitting. The

non-drive threads are sometimes referred to asthe free-cup and the drive-side threads are known as the fixed cup. Do not grease the drive side of a bottom bracket with Italian threads.

4

Toolbox

� Measuring callipers � Ruler � Spanner� Cartridge bottom bracket remover � Grease

Parts of a cartridge bottom bracket

Non-drive(free-cup)

side

Bottom-bracket axle

Drive (fixed-cup) side

STEP LOCATOR

1 2 3 4 5

72

Page 73: Bicycle Repair Manual

Cartridge bottom bracket

Measure the width of the bottom-bracketshell with a ruler. The shell forms part of

the bike’s frame and will be either 68mm (23⁄4in)or 73mm (3in) wide. This width determines thewidth of the bracket unit you need to buy.

2

Insert the bottom bracket from the drive(fixed-cup) side using the remover tool. Fit

the teeth of the tool into the indentations of thebottom bracket (see enlargement).

• Insert the non-drive (free-cup) side when thedrive side is almost in position. Use the removerto screw it in a few turns. Fully tighten the driveside, then the non-drive side.

5

Remove both the cranks (see pp.68–9),insert a bottom-bracket remover into the

non-drive side of the bracket and turn theremover anticlockwise with a spanner.

• Repeat on the other side, turning clockwise.Turn it anticlockwise if your bike has an Italian-threaded bottom bracket (marked 36 x 1).

3

73

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STEP LOCATOR

1234

MAINTAINING YOUR TRANSMISSION • BOTTOM BRACKETS74

Hollow-axlebottom bracketThe hollow-axle system was developed toincrease the strength of the bottom bracket.The bearings on which the axle runs screwonto the outside of the bottom bracket shell,which allows a large diameter axle to be usedthat is hollow, light, and stronger than otheraxles. Since the bearings are further apartthan on other types of bottom bracket, theyencounter less torque, which increases theirlifespan. However, they will still eventuallywear and have to be replaced, so you willneed to know how to remove and replacethem. You will also need to follow these stepsif you want to upgrade to this system.

Installing a hollow-axle bottom bracket

The faces of the bottom bracket shell mustbe flat and parallel. This requires specialist

equipment, so get the frame checked at a bike shop.

• Measure the width of the bottom bracket shell,then check the manufacturer’s instructions todetermine how many spacers are required and onwhich cup to put them.

• Grease the threads of the cups and place thenecessary spacers on them.

1

Push the left-hand crank onto the non-drive side of the axle.

• The crank must be mounted at 180-degrees tothe right-hand crank. To do this, match the widenotch on the axle with the wide tooth on the crank.

• Unlike other bottom bracket systems, it is notnecessary to have a dry interface between thecrank and axle. Put a little grease on the axlebefore you fit the crank.

4

Toolbox

� Hollow-axle cup tool � Hollow-axle crank cap tool� Allen key multi-tool

6

Non-driveside cup

Crank cap bolt

Left-handcrank

5

Pinch bolt

Chainring

Combineddrive-side

cup andsleeve

Axle

Spacers

Parts of a hollow-axle bottom bracket

Page 75: Bicycle Repair Manual

Hollow-axle bottom bracket 75

Screw the cups into the frame as far as youcan with your fingers (inset).

• The drive-side cup screws in anti-clockwise, andthe non-drive side cup screws in clockwise.

• Secure the cups on each side by tighteningthem with the hollow-axle cup tool (main image).

• Grease the axle in preparation for pushing itthrough the cups.

2 Hold the drive side (right-hand) crank and push the axle through the hole in

the centre of the drive-side cup.

• Continue pushing until the end of the axlepops out of the non-drive side cup.

• You may encounter resistance, especially as youpush the axle through the non-drive side cup. Ifthis happens, give the centre of the crank a sharptap with a plastic mallet.

3

Grease the threads of the crank cap bolt,and screw it into place with your fingers.

• Tighten the crank cap bolt with the crank captool, which draws the crank onto the axle.

• Do not over-tighten the crank cap bolt. Rotatethe cranks and if the axle is stiff, loosen the crankcap bolt a little.

5 Tighten the crank pinch bolts with anAllen key to fix the crank in place.

• The pinch bolts work as a pair, so must beequally tight. Tighten them in sequence by screwingin the first a little, then screwing in the other bythe same amount. Repeat until both bolts aretight, but do not use excessive force.

• If you have access to a torque wrench, use it totighten the bolts to the manufacturer's instructions.

6

Page 76: Bicycle Repair Manual

MAINTAINING YOUR TRANSMISSION • BOTTOM BRACKETS

BMX bottombracketMany types of bottom bracket are fitted toBMX bikes. The type used in this sequence of steps is similar to the type fitted to manychildren’s bikes.

The biggest difference between this kindof BMX bracket and normal bottom bracketsis that the threads securing it in the frameare on the axle and not inside the bottom-bracket shell. The axle has a cup and conebearing system, a little like an open-bearinghub (see pp.100–1). The drive-side cone,chainring, and axle are made in one piece,and the cranks bolt on to them. This kind of chainset and bottom bracket is called a 3-piece chainset. Screwing the locknut on to the cone needs practising to ensure thatthe bottom bracket is adjusted successfully.

Setting up a BMXbottom bracket

Take out the captive bolt at the centre ofthe non-drive side crank, then loosen the

crank bolt on the side.

1

Put the newly greased drive-side bearingsback into their cup, then insert the axle so

that it sticks out of the non-drive side.

• Put the greased, non-drive side bearings overthe axle and into their cup.

• Make sure that the non-drive bearings aresitting square inside their cup.

4

Toolbox

� Allen key multi-tool � Peg spanner� Spanners � Grease � Degreaser

Parts of a BMX bottom bracket

Non-drive side cup

Chainring

Non-driveside bearings

Non-driveside cone

Drive-side cup

Drive-side bearings

Axle threads

Spacing washer

Locknut

Drive-side cone

Axle

STEP LOCATOR

1 2 3 4 5 6

76

Page 77: Bicycle Repair Manual

BMX bottom bracket

Remove the crank. Hold the non-drivecone still with a peg spanner while

removing the locknut with a spanner.

• Remove the spacer and the cone and pull outthe non-drive bearings from the cup, which islocated inside the bottom-bracket shell.

• Inspect, clean, and degrease the cone.

2

Put the non-drive cone and spacer overthe axle and screw the cone on to the

bearings with the peg spanner. Screw the locknuton to the axle.

• Hold the cone in place against the bearings andscrew the locknut down on to it. Then screw thecone back a little to the locknut. A bit of play inthe axle is permissible, but too much will throwoff the chain.

5 Put the spacer back on the non-drive side of the axle and then push the crank

back on to it.

• Tighten the captive bolt in the middle of thecrank, then tighten the retaining bolt on its side.

6

Take out the drive side of the bottombracket once you have removed the locknut

and cone from the non-drive side.

• Hold the drive side by the drive-side crank andclean and degrease the bearings. Replace anyworn bearings and grease the clean bearings.

• Inspect the cups while the drive side is out ofthe bike. Replace any worn cups or cones.

3

77

Page 78: Bicycle Repair Manual

MAINTAINING YOUR TRANSMISSION • PEDALS

How they workThe two pedals transfer the push from therider’s legs and feet into both cranks which,in turn, rotate the axle in the bottom bracket.The body of a pedal rotates around an axleand is supported on bearings that are eitheropen or held within a cartridge. The pedal’saxle screws into the crank.

Pedals should grip a rider’s feet in someway. For example, studs that prevent footslippage will help a rider who makes frequentstops, such as a commuter in heavy traffic.Some flat pedals are fitted with toe-clips and straps that hold the front of the foot,although they can interfere with the foot as the rider tries to remove it. Clipless pedals hold the foot securely, while releasing it easily whenever the rider wants.

There are two types of pedal, flat and clipless. Pedals with open bearings require regular inspection and lubrication. Clipless pedalsmust be lubricated to ensure easy foot release. Cleats should be correctly fitted to the rider’s shoes and regularly inspected for wear.

PEDALS

FLAT PEDAL ANATOMY

Converting energyPedals are the inventionthat defines cycling. Theyare the first step in theprocess of convertinghuman energy intomechanical motion.

Two bearings on the pedal’s axleare held in place by a cone andlockring that screw on to theouter end of the axle. A knurledretainer attaches the pedal bodyto the axle. The cone(not visible) and thelockring can beadjusted to permit the freerotation of the body aroundthe axle, without any play.

AxleScrews into the crank

Knurled retainerHolds the body on to the axle

Pedal bodyRotates on

the axle

CrankTransfers power tothe bottom bracket

LocknutHolds thecone in place

118 78

Ball-bearingsAllow the body to rotate around the axle

Page 79: Bicycle Repair Manual

PedalConnects the rider’s foot

to the transmission

1179How they work

Page 80: Bicycle Repair Manual

MAINTAINING YOUR TRANSMISSION • PEDALS

Pedal axleThe axle of a pedal is usually made fromsteel and the cranks from aluminium alloy.This creates a materials’ interface where achemical reaction can take place betweenthe two metals, so it is important that youcoat the threads with grease before you putpedals on your bike. The tools to remove theaxles are specific to the make of the pedals,and will be either supplied with the pedals oravailable at a good bike shop.

Most pedals contain two bearings onwhich the pedal body revolves around itsaxle. These sometimes need replacing; in the case of ball-bearings, they need regularcleaning, checking, and greasing.

Pedal axles can be damaged by an impactor during a fall, and a bent axle can causeriding discomfort or even injury. Afterremoving the pedals, rotate their axles by hand, feeling for the tight spots that are evidence of a bent axle.

Removing and lubricating a pedal axle

Place a spanner on the flats of the axle toremove a pedal.

• Turn the spanner anticlockwise for the rightpedal, which has a right-hand thread, and clockwisefor the left pedal, which has a left-hand thread.

• Steady the opposite crank with your hand togive you something to push against.

1

Lift the axle from the pedal once youhave fully unscrewed the retainer nut.

• Clean the axle with degreaser and inspect it. If the axle is bent, it will need replacing.

• Replace the bearings on the end of the axle ifthey are worn.

4

Toolbox

� 15mm bike spanner � Allen key multi-tool� Remover tool � Degreaser � Grease

Parts of a pedal

Pedal bodyCleat-releasemechanism

Release tensionadjuster

Retainer

Pedal axle

Spannerflats

80

STEP LOCATOR

1 2 3 4 5 6

Page 81: Bicycle Repair Manual

Pedal axle

Hold the removed pedal, with the axleupwards, in a vice.

• Remove the axle by using a remover tool thatfits over the knurled retainer connecting the axle to the pedal.

2

Hold the cone with one spanner and removethe locknut with another. The cone and

locknut hold the bearings on the end of the axle.

• Remove the cone, then the old bearings. Cleanthe end of the axle.

• Set the new bearings in grease and screw thecone back on top of them. Then lock the conewith the locknut.

5 Grease the inner bearing to prolong itslife. If it is worn, the whole axle assembly

must be replaced.

• Push some grease down into the bearing aftercleaning the axle. To reassemble the pedal, repeatSteps 1–4 in reverse order.

6

Ensure that the remover tool fits snuglyon to the retainer. The retainer may be

damaged if you do not.

• Place a spanner on the flats of the removertool in place and turn it to remove the retainer.

• Turn the spanner clockwise for the right axleretainer, which has a left-hand thread, andanticlockwise for the left axle retainer, which has a right-hand thread.

3

81

Page 82: Bicycle Repair Manual

MAINTAINING YOUR TRANSMISSION • PEDALS82

Clipless pedals were developed in response to the racing cyclist’s need to apply powerthroughout the entire pedal revolution. They hold the foot to the pedal by lockingon to a cleat attached to the sole of theshoe. The mechanism that holds the cleat is spring-loaded – the foot is released byturning the heel outwards.

The release spring is an essential workingpart and must be kept clean and well lubricated. Use light oils on road pedals

and heavier oils on off-road pedals. Wipe oilfrom the pedal body to stop your foot fromslipping. The mechanism lets the foot pivotaround its long axis during each revolution.The oil applied to the release spring is enoughto keep the mechanism working well.

Time road pedalThese pedals offer arange of movement thatcan be adjusted to suitthe requirements of individual riders. Keepthem well maintained byscrubbing regularly withdegreaser, using a stiffbrush. Wash this off,then lubricate the releasespring with heavier oil,dribbling it from a can.

Look road pedalA small Allen bolt in thecentre of these easy-to-maintain pedals altersthe degree to which thefoot can pivot when pedalling. Adjust thefoot-release tension viathe yellow button on thepedal’s back plate. Everynow and then, dribble oil between the backplate and body.

Clipless pedals

Toolbox

� 15mm bike spanner � Allen key multi-tool� Degreaser � Stiff brush � Oil

Release spring

Pivot adjuster

Road pedals are light, supportive, and,because of the greater speeds involved in road riding, aerodynamic. They need to engage and release the feet with equal

ease as well as holding the foot securely.Ideally, you should be able to adjust themaccording to how much movement yourfeet make during pedalling.

ROAD PEDALS

Pedal body

Releasetension

adjuster

Top face

Bottom face

Top face

Bottom face

Retentionmechanism

Pedal body

Back plate

Page 83: Bicycle Repair Manual

Clipless pedals 83

Time off-road pedalThe few moving parts of this simple pedal areprotected in the body ofthe pedal. Keep the partsclean and dribble a littleheavy oil into the pointwhere the release barenters the pedal body. If necessary, replace thebearings and axles (seepp.80–1).

Release tensionadjuster

Release bar

Off-road pedals are fitted with retentionmechanisms on both sides so that therider’s feet can attach to the pedal no

matter which way up it is. The pedals alsolet mud pass through to prevent themfrom becoming clogged.

Shimano off-road pedalThe open design of thispedal allows good mudclearance but exposes the pedal’s retentionmechanism to the elements. Clean anddegrease the pedals regularly and lubricatethe moving parts with a heavy lubricant. Therelease tension adjuster ison the back plate of thisdouble-sided pedal.

Crank Brothers pedalThis is an open designwith excellent mud clearance and very fewmoving parts – the retention mechanism is just a simple spring. Clean the pedals regularly,and very occasionally re-grease the bearingsusing a grease gun and a special adaptor that issold with the pedals.

OFF-ROAD PEDALS

Axlethread

Retentionmechanism

Bottom face

Bottom face

Plan view

Profile view

Top face

Top faceRelease bar

Open space

Retentionmechanism

Threads Release bar

Pedal axle

Page 84: Bicycle Repair Manual

MAINTAINING YOUR TRANSMISSION • PEDALS

Pedal cleatsClipless pedals are designed to hold your feetfirmly in place, so it is important that thecleats on the pedals are positioned correctlyon the sole of your shoes. The right positionalso enables you to transfer the maximumamount of leg power into the pedals.

Once you have set up the cleats, youmight find that your feet try to return totheir natural position as you ride. Alter thecleat’s angle to accommodate this. However,do not alter its fore and aft position becausethe position shown here is the most efficientfor applying power to the pedals.

The steps in this sequence show an off-road pedal (see pp.82–3), but the principlesare the same for road pedals.

Fitting a pedal cleat

Put on your cycling shoes and mark themon the outer side where your foot is widest.

This point is usually slightly behind the smallesttoe and is in line with the ball of the foot. Theaim of setting up a cleat is to make sure that this part of your foot is exactly above the pedalaxle when you ride.

1

Put on your cycling shoes and sit on yourbike, engaging the cleats in the pedals.

• Ask someone to check from the side that theinitial mark you made is over the pedal axle.

• Go for a ride and check whether your feet tryto turn in or out on the pedals.

4

Toolbox

� White marker pen � Silicone sealant� Allen keys � Screwdriver

Fixingbolts

Cleat

Recessed cleat plate

In-shoe threads for fixing bolts

STEP LOCATOR

1 2 3 4 5 6

Parts of a pedal cleat

84

Page 85: Bicycle Repair Manual

Pedal cleats

Take off your shoes and continue the markyou made with a straight line across the

sole of your shoe, from outside to inside. This linemust be at right angles to the initial mark andshould end on the inner side of the shoe, in linewith the initial mark.

2

Adjust the cleats to accommodate any footposition changes your test ride reveals, but

keep the cleat centre over the axle.

• Mark the sole of your shoes all around thecleat, so that you can line it up again.

• Remove the cleat, put anti-seize compound onthe screw threads and line the cleat up with themarks you made. Tighten the cleat.

5 Seal the Allen heads on the bolts thatsecure the cleats to off-road shoes. These

heads can fill with grit, causing them to loseshape and making it difficult to replace the cleatswhen they wear down. Prevent this by filling theAllen heads with blobs of a silicone sealantavailable from DIY shops.

6

Place the cleat on the shoe so that the lineruns exactly through its centre. Some cleats

are marked to help with this alignment.

• Make sure that the horizontal axis of the cleatis exactly parallel with the line you made.

• Secure the cleat in place with the screws orAllen bolts provided.

3

85

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4

Page 87: Bicycle Repair Manual

STEERING ANDSteering gives you control

of a bike’s handling and

direction. Regularly check

and maintain the headset,

handlebar, wheels, and

hubs to safeguard their

reliability at all times.

WH

EELS

Page 88: Bicycle Repair Manual

STEERING AND WHEELS • HEADSETS

HEADSETSA headset allows the bike to be steered. The headset mustbe properly adjusted to allow smooth, safe steering andto prolong its life. The bearings and bearing surfacesneed regular inspection and lubrication and anythingthat is worn must be replaced at once.

How they workThe main function of the headset is to enable the rider to change the direction of the front wheel under anyconditions. There are two types of headset, threaded and threadless, and both hold the front fork securely in the head tube, while simultaneously allowing the fork to turn freely.

The headset rotates on bearings, which are held inplace by cups, one above the head tube, the other below.For the forks to turn freely, these two cups press on thebearings just enough to prevent any play in the part ofthe fork known as the steerer tube. The way this pressure(also known as load) is achieved varies between thethreaded and threadless headsets.

THREADLESS HEADSET ANATOMY

Top bearingsAllow the steerer tube toturn in the headset

SpacerSits on top of the bearings

Fork crownTurns the fork

Star washerGrips the steerer tube

The stem cap bolt at the top of a threadlessheadset screws into a star washer below. Sometypes of threadlessheadset contain a wedgeinstead of a star washer.When the bolt is turnedwith an Allen key, itpushes the stem andspacer down on to thebearings in the top andbottom cups, and pulls up the steerer tube. Thebottom cup covers thebearings that sit on thefork crown race at thetop of the fork crown. As a result, sufficient load is placed on bothbearings to enable thefront fork to turn freelybut without play.

Stem capbolt

Pulls thesteerer tube

upwards

Top cupLoads thebearings

BottombearingsAllow thefork to turn

Bottom cupLoads thebearings

StemLinks handlebar and headset

Steerer tubeConnects the forkto the headset

88

Page 89: Bicycle Repair Manual

Steering effectivelyA headset allows the rider tosteer the front wheel effectivelyand confidently. The handlebar,which is connected to the steerer tube by the stem, turnsthe fork and the front wheel.

Screwing the top cup down the thread of the steererplaces a load on the top bearings to the point wherethe forks turn freely but without play. The cup, andconsequently the front fork, is then locked in placeby a lockring that also screws down the threadedsteerer. The stem is attached to the headset bytightening the stem’s expander bolt, which pulls up a wedge and jams the stem’s quill inside thethreaded steerer.

THREADED HEADSET ANATOMY

Top cupLoads thebearings

StemLinks the

handlebarand headset

QuillFits inside the

threadedsteerer Lockring

Locks the topcup in place

WedgeJams the quill inthe steerer

ForkHolds and turnsthe front wheel

Top bearingsAllow the steererto turn in theheadset

Bottom bearingsAllow the fork to turn

Threaded steererConnects theheadset to the fork

89

HeadsetHolds thefork in thehead tube

HandlebarSteers thefrontwheel

Expander boltDraws up the wedge

Page 90: Bicycle Repair Manual

STEERING AND WHEELS • HEADSETS

Threadless headsetTo determine whether your bike is equippedwith a threadless or a threaded headset, lookat the stem. If you can see bolts on the sideof the part that sits on top of the head tube,it is a threadless headset.

A number of different types of threadlessheadset can be fitted to modern bikes. Theserange from the type that has both top andbottom cups, like the traditional headset, toothers, such as the headset illustrated here,where the bearing surfaces fit inside thehead tube. All the various types of headsetwork on the same principle and are takenapart in a similar way.

Occasionally, you need to strip down theheadset in order to check it for wear and toclean and lubricate the bearings. If you findany cups or bearing surfaces are worn, youwill need to replace the whole headset. Thisjob requires specialist equipment and is bestleft to the experts in a good bike shop.

Adjusting and cleaning athreadless headset

Remove the stem cap bolt from the centreof the stem cap with an Allen key. This bolt

loads the headset to prevent play in it, ratherthan securing the stem.

1

Lower the fork and lift off the top spacersand either the top cup or bearing cover,

depending on the type of threadless headset.

• Clean, degrease, and look at the bottom bearing.If there are no signs of wear, grease the bearing.

• Take the centring wedge out of the head tube.Clean the bearings, bearing surfaces (inset), andbearing cover or top cup . Examine for wear, putnew grease on the bearings and re-install.

4

Toolbox

� Allen key multi-tool � Degreaser � Grease

Parts of a threadless headset

Bottom cup

Stem cap boltStem cap

Top bearing cover Top race

90

STEP LOCATOR

1 2 3 4 5

Page 91: Bicycle Repair Manual

Threadless headset

Loosen the clamp bolts on the side of thestem once you have removed the cap bolt.

The stem and handlebar assembly are now free. It is the stem clamp bolts that secure the stem to the steerer.

2 Take hold of the front fork, then lift thestem and handlebar from the steerer. You

can leave these to hang out of the way, supportedby the brake and gear cables.

3

91

Put the fork back into the head tube and replace the centring wedge, bearing

cover, and spacers.

• Put the handlebar and stem back on top of the steerer.

• Load the headset by tightening the stem capbolt to a point where the handlebar turns freely,but there is no play in the headset. Secure thestem in place by tightening the clamp bolts.

• Apply the front brake and try to push the bikeforwards to check that the headset is not loose.

5

Page 92: Bicycle Repair Manual

STEERING AND WHEELS • HEADSETS

Threaded headsetOlder bikes and children’s bikes are equippedwith threaded headsets. This type of headsetis designed to make it easy to raise andlower the stem whenever you want tochange the height of the handlebar andadjust your riding position.

The headset’s top cup and the locknutthat holds it in place are both screwed on tothe steerer. The stem is equipped with a shaft,or quill, that fits inside the steerer. For safetyreasons, you should never raise a stem abovethe limit marked on its quill.

On some even older headsets the top cupscrews down. Its serrated top edge is held inplace by a clamp bolt on a similarly serratedlockring assembly. When the clamp bolt isloosened, the top cup screws off.

Remember to disconnect the brakesbefore you start working on the headset and make sure that you reconnect themwhen you have finished. Before the stem is replaced into the steerer of the headset,coat the quill with grease (see pp.30–1).

Servicing a threadedheadset

Undo the Allen bolt in the stem centre andknock it downwards with a plastic mallet

to free the steerer. The stem is secured into thesteerer by an expander bolt which, as it istightened, draws a wedge up inside the quill.

• Lift the stem from the steerer.

1

Degrease all the bearing surfaces of thetop and bottom cups, and of the races. You

can access the top bearings by pushing the forkup the head tube and holding it there.

• Inspect the bearing surfaces and if any aredamaged, you need to fit a new headset – this is best left to a good bike shop.

4

Toolbox

� 6mm Allen key � Grease � Degreaser � 30mmand 32mm headset spanners � Plastic mallet

Parts of a threaded headset

Fork crown race

Top cup

Bottom cup

LocknutSpacer

Top race

92

STEP LOCATOR

1 2 3 4 5 6

Page 93: Bicycle Repair Manual

Threaded headset

Unscrew the locknut while holding the topcup still with a headset spanner.

• Spread newspaper on the floor to catch loosebearings that may drop out of the top cup.

• Lift off the spacers, then unscrew the top cupupwards from the steerer.

2

Grease both the top and bottom bearingsor set loose bearings in grease inside each cup.

• Completely unscrew the top cup to remove the bearings. Set the bearings individually in thegreased cups and screw the top cup back on.Bearings held in cages can be greased in situ so long as they are not worn out.

5 Screw the top cup down on to the topbearings. Replace the spacers and locknut.

• Adjust the top cup so that steering is free.

• Pull the fork to check there is no forwardmovement in the headset.

• Replace the spacer, hold the top cup with aspanner, and tighten the locknut on to it.

• Replace the stem and handlebar.

6

Lower the fork to reveal the bearings inthe bottom cup. Screwing the top cup

upwards allows this to happen. Although mostheadsets have ball-bearings held in cages, watchout for loose bearings that may drop out of thebottom cup. Some headsets have roller bearings –treat these as ball-bearings in the following steps.

3

93

Page 94: Bicycle Repair Manual

STEERING AND WHEELS • HANDLEBARS

Owners of road bikes sometimes want tochange the handlebar to a different shape,often to suit the proportions of their body orbecause of their cycling needs. Some cyclistswant to replace a drop handlebar with astraight, or flat, bar. Others may want toreplace their existing straight bars with riserbars, or vice versa. Riser bars, which are fittedto mountain bikes, are straight in the centre,then rise up to become straight where thegrips are. They are fitted the same way as a straight handlebar.

The steps in this sequence apply to allstraight handlebars, whatever the reason forreplacing them. However, when replacing adrop handlebar with a straight bar, it willnecessary to swap the brake levers for leversthat work with flat or riser bars. Some ofthese steps will also be useful when fittingnew grips, brake levers, gear-shifters, or bar-ends to an existing handlebar.

Fitting a straight handlebar

Remove any raised bit of metal inside thestem clamp with a medium, half-round file

(inset). Smooth the area with emery paper.

• Place the straight handlebar into the stem clampand screw in the clamp bolts. Check that the baris centred before tightening it fully. If you arefitting a riser bar, decide what angle of sweep you want it to be before tightening the bolts.

1

Toolbox

� Half-round file � Emery paper � Ruler� Allen key multi-tool � Hairspray

94

STEP LOCATOR

1 2 3 4 5

HANDLEBARSMost modern bikes are fitted with either straight or drop handlebars. A rider must be able to rely totally on the handlebar, so for safety reasons, a handlebar must be replaced at once if scratches, stressmarks, or cracks develop on the surface.

Straight handlebar

Parts of a straight handlebar

Plastic plug

Straighthandlebar

Brake leverClamp bolt

Grip

Ringclamp

Shifter unitBar-end

Page 95: Bicycle Repair Manual

Straight handlebar

Slide the grips on to the handlebar whilethey are still wet with hairspray.

• Push the grips further on if you are fitting bar-ends to allow for the width of the bar-end clamp.

• Fit grip-locks to hold the grips in place andprevent them from twisting while you are riding.

4 Clamp on the bar-ends. Line them upparallel with the angle of your stem to

begin with, then adjust their angle to suit yourown preference after riding.

• Put a plastic plug in each end of the handlebarto prevent injury in the event of a fall.

5

Spray hairspray into the handlebar grips tohelp the grips to slide on to the handlebar.

When the hairspray dries, the grips will fit tightlyto the handlebars.

3Secure the ring clamp of the brake leverto the handlebar. Like road brake levers,

off-road levers have a ring clamp that fits overand secures them to the handlebar. Some off-roadbrake levers have integrated shift levers with onlyone clamp. However, some are separate so thereare two clamps to go over the handlebar.

2

95

Page 96: Bicycle Repair Manual

STEERING AND WHEELS • HANDLEBARS

Drop handlebarRoad-riding cyclists often choose to fit a drop handlebar to their bikes so that their bodies can adopt a lower and moreaerodynamic position than the more erectposture of a cyclist who uses a straight bar.However, the handlebar should never bepositioned so low that the cyclist’s breathingis restricted when leaning forwards andholding the bottom of the bar.

A drop handlebar must be replacedimmediately if any cracks develop on itssurface. The steps in this sequence will showhow to replace a drop handlebar and how tofit, and therefore how to re-position, brakelevers. Cyclists with larger hands and longarms may prefer to mount the levers lowerdown the handlebar than the ideal positionshown here.

Regularly replace the handlebar tape asshown in Steps 5 and 6, and insert a plug ineach end of the handlebar after taping toprevent possible injury in a fall.

Fitting a drop handlebar

Use a medium, half-round file to removeany raised areas of metal inside the part

of the stem that clamps the bar in place. Theseraised areas can bite into the handlebar, eventuallycausing them to fracture.

• Smooth the filed surface with emery paper.

1

Secure the levers of a Campagnolobrake/shift to the handlebar by tightening

a bolt on the outside of the hood with an Allenkey. Pull the lever hood cover forwards to accessthe bolt. The bolt on Shimano levers is furtherdown the outer side of the lever hood so that you need to put your Allen key into a recess under the rubber cover.

4

Toolbox

� Half-round file � Emery paper� Allen key multi-tool

Parts of a drop handlebar

Brakelever hood

Drop handlebar

Handlebar tape

Rubber cover

Cable groove

96

STEP LOCATOR

1 2 3 4 5 6

Brake lever

Page 97: Bicycle Repair Manual

Drop handlebar

Fit the new handlebar and tighten up theclamp bolts. Before you secure the bolts,

try to line up the flat part of the bottom of thehandlebar with a point just below the back brake.

2

Start taping at one end ofthe handlebar.

• Wind upwards, covering halfof the previous turn with eachsubsequent turn.

• Keep the tape tight at all times.

5

Pull the cover of thebrake lever hood

forwards and place a shortlength of tape over each steel ring.

• Wind the tape in one turnfrom the bottom to the top of thelever hood. When you reach the top of the handlebar, secure thetape with insulating tape.

6

Slide the steel ring of the brake lever overthe handlebar. This ring clamps the lever

to the handlebar.

• Attach the bolt in the brake lever hood to thescrew thread on the ring and tighten.

3

97

Page 98: Bicycle Repair Manual

STEERING AND WHEELS • HUBS

HUBSThere are two types of hub, open-bearing and cartridge. The conesand bearings of open-bearing hubs must be lubricated regularlyand adjusted to let the hubs spin freely, with little play. The bearingsin both types need regular checking and replacing when worn.

How they workThe hub allows the wheel to revolve. Quick-release mechanisms or nuts secure the axleinto the bike’s frame. The axle remains staticwhile the hub body spins around on bearings.Spokes run from the hub’s flanges to the rimof the wheel – as the hub spins, so does the rim.

The transmission transfers the rider’s powerfrom the pedals to the rear wheel, while thefront wheel is essentially pushed along by therevolutions of the rear. The gears on a bike arelocated on the rear hub, either as a hub-gearunit or as multiple sprockets in the case ofderailleur gears.

The freewheel mechanism, which is also onthe rear hub, allows a rider to cease pedallingwhile the bike is in motion – for example, on a downhill stretch of road. This mechanism ispart of the hub in both hub gears and hubswith cassette sprockets.

Minimizing frictionFree-spinning hubs are an essentialpart of an efficient bike. Theirbearings must create as little friction as possible, so as not toslow the rider’s forward progress.

The axle of a cartridge hub is not threaded, so the bearings arepushed on to each end of the axle and covered by a seal. When the hub is assembled, the bearings sit in the hub body, just to the outside of the flanges, with the axle running through them.Lockrings ensure that everything is held in place.

EXPLODED CARTRIDGE HUB

Hub bodyContains theaxle

SealCovers thebearings

AxleRotates the

wheel

Cartidgebearings

Support thehub body

98

FlangeAnchors thespokes to the hub

Page 99: Bicycle Repair Manual

How they work

OPEN-BEARING FRONT HUB ANATOMY

The body on an open-bearing front hub spins on ball-bearings that are set within, and at each end of, the hub body. Each set of bearings is held in place by a cone (not visible) that is screweddown on the thread at the end of the axle. A locknut (not visible)locks the cone in place on the same thread. If the hub is held by aquick-release mechanism, the axle is hollow to allow the quick-release skewer to go through it.

Ball-bearings

Support thehub body

AxleRemains static

as the wheelrevolves

Hub bodyRotatesaroundthe axle

Quick-releaseskewer

Locks the axlein place

99

Open-bearing front hubAllows the wheel torevolve smoothly

Page 100: Bicycle Repair Manual

STEERING AND WHEELS • HUBS

Open-bearing hubHubs are available in two types – open-bearing or cartridge. The open-bearing hubsrequire much more maintenance than thecartridge type (see pp.102–3), since theirbearings need regular inspection, cleaning,and regreasing. As a result, the ability tostrip down and service an open-bearing hubis a skill that can be used repeatedly.

The following steps will help you toremove an axle and a freehub, as well asregrease and retighten the bearings. Theycan be applied to a Shimano front or rearhub and a Campagnolo front hub. However,leave servicing a Campagnolo rear hub tothe experts at a bike shop because itrequires specialist tools.

If you are working on a rear hub, youneed to remove the cassette by followingthe steps on pp.66–7 before tackling thesteps in this sequence.

Overhauling an open-bearing hub

Remove the locknut on the drive side witha spanner while holding the non-drive side

cone with a cone spanner. Some locknuts can beremoved with an ordinary spanner, others with an Allen key.

• Keep holding the non-drive side cone with the cone spanner and remove the drive-side cone with another cone spanner.

1

Take out all the ball-bearings from eachside and clean them with degreaser.

• Replace ball-bearings that are scored or haveflat spots on their surface.

• Insert a layer of grease into each groove, orrace, where the ball-bearings sit.

• Return the ball-bearings to each race, pressingdown firmly so the grease holds them in place.

4Toolbox

� 15mm and 16mm cone spanners (Shimano) � 13mm and 14mm cone spanners (Campagnolo)� Grease � Grease gun (optional) � Allen key multi-tool � Adjustable spanner� 8mm or 10mm Allen key

Parts of an open-bearing hub

Locknut

Non-drive side Drive side

AxleSpacers

Flange

Cone

Flange

Locknut

Freehub bodyHubbody

100

STEP LOCATOR

1 2 3 4 5

Page 101: Bicycle Repair Manual

Open-bearing hub

Pull the axle out from the non-drive side.Be careful not to dislodge any of the ball-

bearings as you do so.

• Clean the cones and axle and then inspectthem for damage. Check to see if the axle is bentby rolling it on a flat surface and looking for anyirregular motion. Replace damaged cones or bentaxles immediately.

2

Fit the new hub body orthe cleaned old one by

reversing Step 3.

• Re-insert the axle from thenon-drive side.

• Tighten the drive cone up tothe bearings and check that theaxle spins freely with minimal play.

• Lock the cone into positionwith the locknut.

• Use the cone spanners to checkthat the non-drive cone is tightagainst its locknut.

5

Insert an Allen key into the 8mm or 10mm Allen bolt located in the centre

of the freehub. This bolt holds the freehub body on to the axle.

• Turn the key anticlockwise to remove thefreehub. You may need a bit of force to loosenthis bolt so use an Allen key with a long handlefor extra leverage.

3

101

Page 102: Bicycle Repair Manual

STEP LOCATOR

STEERING AND WHEELS • HUBS102

Cartridge hubCartridge hubs offer many of the advantagesof cartridge-bearing bottom brackets – forexample, they keep out water and dirt,increasing the life of the bearing. However,unlike many cartridge bottom brackets, youcan change bearings when they wear out.Replacing the bearings is a straightforwardtask that requires special drifts to drive outthe old bearings and drive in the new.

Check the bearings by removing the wheelfrom the bike and spinning it while holdingthe axle. If you feel any roughness thebearings are worn. Excessive play of the hub on the axle is also a sign of wear.

Only the hub is shown in these steps, butyou will deal with the whole wheel. You canalso follow these steps to replace a bent orbroken axle – although rare, it can happen ifa bike hits a bump in the road and the rideris not prepared for it, or when landing jumpson a mountain bike or a BMX.

Overhauling a cartridge hub

Remove the seals from each side of thehub axle. Some seals are retained by a

lockring that is secured with a grub screw; others just require prising off.

• Remember how they look in situ and wherethey fit as you will need to put them back inexactly the same position.

1

Insert the first new cartridge bearing byoffering the bearing square to the hub and

driving it home with a wider drift.

• Knock the bearings in gently. Although it cansometimes take a bit of force to knock the oldbearings out, it should not take too much force to position the new ones in place.

4

Toolbox

� Plastic mallet � Vice � Drifts (suitable for makeof hub – check manufacturer’s instructions)� Allen key multi-tool (optional)

Parts of a cartridge hub (front)

Hub body

1 2 3 4 5 6

Hub flanges

Axle Bearing

Lockring

Page 103: Bicycle Repair Manual

Cartridge hub 103

Rest the hub flange between two blocks ofwood held in a vice.

• Tap the axle down with a plastic mallet. Beconfident when using the mallet, as you may have to be forceful.

• Drive the axle through the upper bearing witha drift. This is a metal cylinder with the samediameter as the centre of the cartridge bearing.

2

Push the second bearing on to the axle,then place the drift on to a flat surface,

such as the flat portion of the vice. If you are notusing a vice, place a piece of thick metal on thework surface or even the floor. The surface mustbe strong enough to absorb the mallet blows.

• Lay the bearing on the drift and tap the axlefully into the bearing.

5 Lower the hub down on to the axle. Makesure that the axle is through the middle of

the bearing you have already fixed inside the hub.

• Use the drifts to tap the hub down so that theaxle goes all the way into the bearing.

• Replace the seals and spacers. Secure the lockrings on to the axle. The grooves on the sealsmust snap back into place or the seals will not work.

6

Take out the axle from the hub body witha bearing still attached to it.

• Lay this bearing on the wooden blocks anddrive the axle through.

• Drift the other bearing out of the hub body, as in Step 2. Do this from behind the bearing, bytapping the drift from the same side of the hubfrom which you removed the axle.

3

Page 104: Bicycle Repair Manual

STEERING AND WHEELS • WHEELS

Removing and refitting a wheel is astraightforward task, but if any of thefollowing steps are overlooked, the wheelmay come loose and compromise the rider’ssafety. The steps are for wheels with quick-release levers that secure them in the drop-outs (the recess in the frame into which theaxle fits). For bikes with axle nuts, looseningand tightening with a spanner corresponds tounlocking and locking the quick-release lever.

Levers are labelled “locked” or “closed” onthe side facing the cyclist when the wheel issecure, and “unlocked” or “open” when it isnot. Check levers are locked before each ride,and during a ride if disc brakes are fitted.

The rim brake needs to be released on thewheel being removed. For V-brakes, unhookthe cable from its cradle; for cantileversunhook the straddle wire from the left brakearm; for callipers, use the quick-release lever.

Removing a rear wheel

Release the brake, shift the chain on tothe smallest sprocket and pull the quick-

release lever away from the bike into the unlockedposition. Some quick-release levers are shaped sothat they bend towards the frame when in thelocked position. This provides a visual check ifnothing is printed on the lever.

1

Toolbox

� Spanners for wheels with axle nuts

Parts of the quick-release system

Quick-releasebody

104

STEP LOCATOR

1 2 3 1 2

WHEELSQuick-release mechanisms help to remove and replace a wheel quickerthan ever before. The tyres are the component that make contact withthe ground. Match the tyres on your bike to the prevailing riding conditions and always be ready to replace worn-out tyres.

Quick-release wheels

Quick-releaselever

Wheel drop-out

Fork

Page 105: Bicycle Repair Manual

Quick-release wheels

Removing a front wheel

Hook the chain out of the way and on tothe peg situated on the inner side of the

right seat stay (if there is one).

• Pull the rear mech back and then lift up therear of the bike.

• Give the tyre a sharp blow from above with the heel of your hand if the wheel does not dropforwards and out of the frame.

2

Lift up the bike to allow the wheel to dropout of the fork.

• Replace the front wheel by reversing Step 1.

• Push the quick-release lever behind the leftfork leg to prevent anything catching it andopening it accidentally.

• Reconnect the brake once the wheel is locked.

2Release the brake. Pull the quick-releaselever to the unlocked position. If the

drop-out has safety lips, the wheel will not comeout of the fork at this stage. These safety lipsprevent the wheel falling out in the unlikely eventof the lever becoming unlocked while you ride.

• Use your fingers to unscrew the nut on theopposite side of the lever until the quick-releaseclears the safety lip.

1

Replace the wheel by introducing the hubaxle to the drop-outs.

• Hook the chain on to the smallest sprocket,then push or pull the wheel backwards.

• Line up the tyre exactly in the middle of thechainstays as you hold the wheel straight.

• Push the quick-release lever into the lockedposition to secure the wheel. Reconnect the brake.

3

105

Page 106: Bicycle Repair Manual

STEP LOCATOR

STEERING AND WHEELS • WHEELS106

Puncture repairWhen you are out on a ride, it is much easierto replace a punctured inner tube with anintact tube rather than painstakingly mendthe puncture. At home, you can repair thepunctured tube with adhesive and a patch. It is still a good idea to carry a repair kit onevery ride, because you might be unluckyenough to get a second puncture and beforced to repair the tube outdoors.

The main point to remember aboutmending a puncture is not to rush any of the stages. If you patiently give the gluetime to dry, closely examine the inside of the tyre, and carefully refit the tube, thenyou will be rewarded with a successful repair.If you miss anything or trap the inner tube,you may get another puncture.

Mending a puncturedinner tube

Take the wheel out of the bike. Place onetyre lever under the tyre bead and lift it off

the rim. Hook this lever around one of the spokes.

• Insert another lever under the tyre near to thehooked lever. Push the second lever forwards andrun it around the whole circumference of the rimto remove one side of the tyre.

• Remove the inner tube from the rim.

1

Take the tyre off the wheel, turn it insideout and thoroughly check the inner surface.

• Remove anything that is sticking through thetyre by pulling it out from the outside of the tyre.

4

Toolbox

� Tyre levers � Crayon � Sandpaper � Chalk� Patch adhesive � Repair patches

Parts of a wheel

Inner tube

1 2 3 4 5

RimTyre Valve

Spoke

Page 107: Bicycle Repair Manual

Puncture repair 107

Inflate the tube a little and listen for thesound of escaping air. Locate the hole, mark

it with a crayon, and let the air out of the tube.

• Spread a thin layer of adhesive over and aroundthe hole (inset). Allow time for it to become tacky.

• Peel the foil from the patch. Press the patchfirmly on to the adhesive for over a minute. Make sure that the edges are flat.

2

Put one side of the tyre fullyback on to the rim. Slightly

inflate the tube, insert the valve intothe hole in the rim, and then workthe tube back inside the tyre.

• Put the other side of thetyre in place by pushingthe valve upwards, thenlifting the section of tyrenext to the valve overthe rim. Work thetyre back around the rim.

• Check that thetyre has not trappedthe tube underneath itbefore fully inflating thetube. To do this, pinch the tyretogether and look around the wholecircumference of the wheel.

5

Use a small piece of sandpaper to dustsome chalk over the patch to prevent excess

adhesive from sticking to the inside of the tyre.

• Leave the tube for a few minutes to make surethat the adhesive has dried.

3

Page 108: Bicycle Repair Manual

STEERING AND WHEELS • WHEELS

Spokes and rimsThe steps in this sequence explain how toreplace a single broken spoke and how totrue a wheel, a term for straightening therim of a wheel. However, replacing multiplespokes, replacing spokes in non-standardwheels, and truing a wheel that has beenbuckled by some kind of impact are jobs that are best left to the experts in a goodbike repair shop.

It is essential to true the wheel afterreplacing a broken spoke because the wheelrim is kept straight by the combined pull of all the spokes acting on it. If one spokebreaks, its pull is missed and the rim as awhole goes out of line.

A wheel jig is needed to true a wheelproperly. This tool holds the wheel securelyin place and its jaws provide a referencepoint either side of the rim to help judgehow out of line the wheel has become.Bringing it in line is a matter of tighteningthe new spoke until it reaches the sametension as the old spoke.

Replacing a spoke andtruing a wheel

Remove the wheel and take off the tyreand inner tube.

• Lift up the rim tape next to the broken spokeand push the spoke upwards and out of the rim. If the head of the spoke is broken, measure thebroken spoke so you can buy the correct length toreplace it. If the break occurred in another place,measure the two pieces to get the right length.

1

Screw the nipple on to the spoke. For thefirst few turns you can use your fingers.

• Go back to Step 2 and check that it is lacedexactly the same way as the spoke four alongfrom it. If it is not laced properly, tensioning thespoke in Steps 5 and 6 could damage the wheel.

4

Toolbox

� Spoke key � Wheel jig � Long-nosed pliers

Parts of a spoke

108

STEP LOCATOR

2

1 3 4 5 6

Nipple head

SpokeBend

Nipple Threads Spoke

Spoke head

Page 109: Bicycle Repair Manual

Spokes and rims

Insert the new spoke, threads first, intothe hub flange from the opposite side to

its two neighbours.

• Lace the new spoke into the wheel, under andover the neighbouring spokes. To do this, look atthe spoke four along and lace the new spokeexactly the same way.

2

Put the wheel into a wheel jig and takeup the remaining slack on the spoke nipple

by tightening it with a spoke key. Make sure thatthe spoke key is precisely the right size for thenipples on the wheel.

• Stop short of making the spoke as tight as itsneighbours at this stage.

5 Use small, measured turns of the spokekey to tension the spoke.

• Rotate the wheel so that the nipple of the newspoke is between the jaws of your jig.

• Note how out of line the rim is, then give thenipple a one-quarter tightening turn and checkagain between the jaws. Repeat and check eachquarter turn until the rim is straight.

6

Push the nipple of the new spoke throughthe rim hole from inside the rim and screw

it on to the spoke.

• Remove the rim tape to make it easier to fit thenipple on to the new spoke.

• Check the rim tape – if you see any splits, or ifit is frayed, replace the tape.

3

109

Page 110: Bicycle Repair Manual

5

Page 111: Bicycle Repair Manual

Trustworthy brakes are

a bike’s most important

component. The braking

system needs to be

adjusted and serviced

with careful precision to

guarantee a rider’s safety

in all conditions.

BRA

KESADJUSTING YOUR

Page 112: Bicycle Repair Manual

ADJUSTING YOUR BRAKES • RIM BRAKES112

RIM BRAKESRim brakes stop a bike by contacting the rim of the wheels.Pads must be checked to ensure that they contact the rimfully and at the same time, and replaced when they are worn.Brake cables must be checked and lubricated regularly.

How they workThe three most common types of rim brake, V-brake,cantilever, and calliper, work in a similar way. A leverpulls a cable, which causes the two brake arms to movetowards each other simultaneously. This action bringsthe two pads into contact with the braking surface ofthe wheel rim. Springs cause the arms to move backwhen the lever is released. Cantilever brakes distributethe cable’s pull via a straddle wire. The inner cable in a V-brake and calliper pulls one arm, while the outer,in resisting this pull, effectively pushes the other arm.

Braking safelyRim brakes must be set upproperly and maintained tovery high standards if theyare to work effectively andsafely on any surface and inall conditions.

The cable of a V-brake is attached to a brakearm by a cable-clamp bolt. When pulled, thecable pulls this arm towards the rim. At thesame time, the cable-guide tube, which is anextension of the cable outer, pushes the other

arm inwards. The two arms pivot around thebrake bosses, pushing the brake pads againstthe braking surface on the rim. Once the cable’spull is released, springs around the pivot boltspush both brake arms apart.

V-BRAKE ANATOMY

Brake padContacts the rim and stops the wheel

Brake armPivots inwards on

a brake boss

Cable-clamp boltAttaches the cable to the brake arm

Cable-guide tubePushes the brake

arm

Pivot boltAnchors thebrake arm to the brake boss

Inner cablePulls thebrake arm

Brake bossAllows the brake arm to pivot

SpringsPush brake arms apart

Page 113: Bicycle Repair Manual

How they work 113

When the rider applies the brake lever it pulls the nipple of the inner cable. As it leaves the lever, thebrake cable runs inside a cable outer, which sits in abarrel adjuster. This barrel adjuster allows the braketravel to be fine-tuned.

Brake leverPulls the cable

Brake armMoves thebrake padstowards the rim

Brake padSlows downthe wheel

Brake leverPulls the

nipple

Barrel adjusterAdjusts brake

travel

Inner cableLinks the brake arm to

the brake lever

Cable outerResists thepull on the

cable

NippleFixes inner cable to brake lever

BRAKE LEVER ANATOMY

Page 114: Bicycle Repair Manual

1234

ADJUSTING YOUR BRAKES • RIM BRAKES

Drop handlebarbrake cableBrake cables on a drop handlebar need to bechanged at regular intervals, although thisdepends on how much the road bike is used.For a heavily used bike, change the brakecables every two months; for a bike riddenlightly two or three times a week, changethe brake cables once a year.

The steps in this sequence are performedon the back brake. Replacing a cable on thefront brake follows the same principles, butthere are no cable guides to thread through.

Brake levers that fit a drop handlebarrequire a brake cable with a pear nipple.Always keep a new cable in the toolbox or workshop as a spare. A rear cable can becut to fit the front as well. Once the cablehas been removed, remember to put a fewdrops of lubricant on the pivots aroundwhich the brake lever moves, and spray some oil into the tube inside the lever hood where the cable is inserted.

Replacing road bikebrake cables

Loosen the cable-clamp bolt on the brakecalliper. Remove the old cable by pulling its

nipple from the lever hood with long-nosed pliers.

• Note exactly where the cable fits in the leverhood to allow you to fit the new one easily.

• If the old cable has broken, remove the part ofthe cable that is still clamped to the calliper.

• Carefully unwind the handlebar tape.

1

Fit each length of cable outer with a metalferrule at both ends. When you apply the

brake, ferrules prevent the cable outers from beingpulled through the cable guides on the frame.

• Make sure that each ferrule is fully pushedhome. Put a little oil on the end of the ferrule tohelp it slide into place and wipe off any excess.

4

Toolbox

� Long-nosed pliers � Cable cutters � Allen key multi-tool � Fine round file

Parts of a brake lever and brake cable

Brake cable

6

5

STEP LOCATOR

114

Brake lever

Brake leverhood

Pear-shaped nipple

Brakecable

Campagnolo Ergoshift

Page 115: Bicycle Repair Manual

Drop handlebar brake cable

Insert the new, greased cable into thecradle on the lever in which the nipple sits.

• Thread the cable into the tube in the leverhood. Push it in and look for it coming out of theback of the lever hood. Now pull it through thelever hood from behind.

• Make sure that the nipple is seated in the brakelever cradle when the cable is all the way through.

2

Thread the cable through the first lengthof cable outer and the first cable guide.

• Pull the cable all the way through and insert itinto the next guide, then the next outer.

• Push the cable outers firmly into the guides, toensure there is no slack when applying the brakes.

• Use a fine round file to file out any tight cableguides. Do not file more than you have to.

5 Pull the cable through the cable-clampbolt on the calliper until each brake pad is

about 2mm from the wheel rim.

• Hold the cable and tighten the clamp bolt. If thebrake has a quick release, ensure that it is in theclosed position before tightening the clamp bolt.

• Follow Steps 5 and 6 on p.97 to re-tape thehandlebar, with either new or existing tape.

6

Cut the new cable outer to length withgood-quality cable cutters. Measure the old

outer and cut the new one to the same length.

• Always cut between the spirals of the cable outer.

• Dribble oil into the cable outer, holding it whilethe oil runs down to coat the inside.

• Renew cable outers at regular intervals.

3

115

Page 116: Bicycle Repair Manual

456

ADJUSTING YOUR BRAKES • RIM BRAKES

Straight handlebarbrake cableReplacing the brake cable inners and outersis a job that should be done fairly often on a mountain bike – about once every six to12 months. They also need replacing if theystart fraying and become worn. The hybridbike in this sequence has V-brakes, but somemountain bikes are equipped with cantileverbrakes. Fitting cables is similar for both.

Brake cables also require regular cleaningand lubricating, especially if the bike has been ridden consistently in wet weather. Allbrake levers that fit on to a straight or riserhandlebar require a cable with a barrel nipple.

Regardless of the manufacturer, the barrelnipple fits into the brake lever in the sameway. Remember to use ferrules on both endsof every length of new outer cable. Crimp acable tidy on the end of the cable, onceeverything is secure and working as it should.

In these steps the tyre is removed fromthe wheel to show clearly what is happening.

Replacing V-brake cableson a hybrid bike

Undo the cable-clamp bolt on the brake.Note where the nipple sits in the cradle

that is part of the lever and remove the cablefrom inside the brake lever by pulling it out with long-nosed pliers.

• Check the outer cables. If they are not worn,you can use them again. Flush them out withdegreaser and dribble oil into them.

1

Attach the cable to the brake arm byinserting it in the cable guide tube and

then pull it through the cable-clamp bolt.

• Keep the cable under tension and check thateach length of cable outer is properly seated in the cable guides.

• Pull the cable to bring the brake pads closer tothe rim. Tighten the clamp bolt when the pads areabout 2mm from the rim.

4

Toolbox

� Long-nosed pliers � Cable cutters� Allen key multi-tool � Cable pullers (optional)

Parts of a brake lever and a brake cable

Brake cable

116

Brake lever Barrel adjuster

Reachadjuster

STEP LOCATOR

123

Nipple

Brakecable

Ring clampBrake lever

Page 117: Bicycle Repair Manual

Straight handlebar brake cable

Cut new cable outers to the same lengthas the outers you removed or measure them

up on your bike and trim as needed. Buy cableouter either in a roll or in pre-cut lengths withinners in a cable kit. The pre-cut lengths may betoo long for your bike so you may still have to cutto fit.

• Dribble oil into each cable outer and push ametal ferrule on to each end.

2

Pull the brake lever until the brake is fullyapplied. This ensures that all cable outers

are bedded in and all bolts are tight.

• Undo the cable-clamp bolt and repeat Step 4 if the cable slips through the clamp bolt or aferrule is not seated properly.

5 Cut off any excess cable once the cablesare bedded in.

• Leave about 4cm (11⁄2in) of free cable after thecable-clamp bolt.

• Crimp a cable tidy on the end of the cable toprevent it from fraying.

6

Grease the new inner and thread it intothe brake lever. When it shows through the

barrel adjuster, pull it from this side of the leveruntil the nipple is seated in the lever cradle.

• Thread the cable through the lengths of cableouter and seat the cable outers in the cableguides of the frame.

3

117

Page 118: Bicycle Repair Manual

STEP LOCATOR

ADJUSTING YOUR BRAKES • RIM BRAKES118

Calliper brakeMaintaining calliper brakes is a question ofregularly checking the action of the brakelever. If you have to pull it too far before thebrake bites, the brake needs adjusting. Checkthe brake pads for wear and alignment, andensure that they contact the braking surfaceof the rims simultaneously.

How far the lever has to be pulled beforethe brake comes on depends on the rider.People with smaller hands may prefer moretravel in the lever before the brake bites,because they will pull with more strengththe closer the lever is to the handlebar.

Apart from their quick releases, all dual-pivot calliper brakes (such as the Shimanobrakes shown here) work in the same way,regardless of the manufacturer. This meansthat you should be able to apply these stepsto your bike, whatever its brakes.

Adjusting a calliper brake

Periodically check for pad wear. If thepads are wearing down towards half their

original depth they must be replaced.

• Undo the Allen key pad retainer and push outthe pad. If the pad and shoe are a complete piece,replace the whole unit, releasing the old pad andfitting the new one with a 5mm Allen key.

1

Pull the brake on with the brake lever andcheck to see if both pads simultaneously

come into contact with the braking surface onthe rim of the wheel.

• Make sure that both sides are working togetherby turning an adjustment screw on the side of thecalliper with an Allen key. This process is called“centring” the brakes.

3

Toolbox

� Full set of Allen keys or Allen key multi-tool � Long-nosed pliers (optional)

Parts of a calliper brake

1 2 3 4

Calliper arm

Centre-fixing bolt

Centring adjustingscrew

Brake shoebolt

Brake shoe

Brake pad

Traveladjuster,

spring,and

washer

1

1

Page 119: Bicycle Repair Manual

Calliper brake 119

Adjust the brake pads so they are directlyin line with the braking surface of the rim.

• Release the 5mm Allen bolt on the pad and linethe pad up with the braking surface.

• Look for pad wear at this point. Pads that havebeen set too low will develop a lip and will needto be replaced.

2

Adjust the brake travel if you have to pullthe brake lever back a long way towards the

handlebar before the wheel stops moving.

• Undo the cable-fixing bolt and squeeze thesides of the calliper until the pads nearly touchthe rim. The brake cable will then move throughthe fixing bolt.

• Tighten the bolt and release the calliper.

4 Press the small button at the side of thebrake lever to move Campagnolo calliper

brake pads away from the rim.

• Restore the pads to their original position bypulling the brake lever towards the handlebaruntil the brakes are on and then push the smallbutton back.

Use a quick-release mechanism when the adjusted brake pads are so close to

the rim that it is impossible to remove the wheel.Campagnolo and Shimano calliper brakes areequipped with different quick-release systems.

• Lift the small lever on the cable-fixing bolt tomake Shimano calliper brake pads move away fromthe rim. After replacing the wheel, lower the lever.

Using quick-releasemechanisms

1

1

Page 120: Bicycle Repair Manual

STEP LOCATOR

ADJUSTING YOUR BRAKES • RIM BRAKES120

V-brakeV-brakes are fitted to most new mountainbikes because they give good stopping power.Maintaining brake performance is crucialbecause of the harsh conditions to whichmountain bikes are sometimes subjected, soknowing how to adjust the brakes at homeand out on the trail is very important.

Pad alignment and brake travel need tobe checked and adjusted regularly to keepthem working properly. Bear in mind that assoon as you ride off-road you will increasebrake pad wear. Even a single ride can renderalready worn pads useless, so change thembefore they need it.

Adjustment in the workshop, especiallypad alignment, is best performed with thetyre removed, since off-road tyres are bulkyand can be in the way. Wheels must run truebefore setting up brakes (see pp.108–9).

Adjusting a V-brake

Check that the stopper pin on each brakearm is seated in the same hole on the

brake bosses. If it is not, remove the pivot bolt,slide the brake arm off the boss, and put the pininto the correct hole.

• Replace the pivot bolt and re-tighten it. If younotice that the brake boss was dry with the armremoved, smear a little grease on it.

1

Re-tension the brakes by hooking thecable back in its cradle.

• Check that the gap between each brake padand the rim of the wheel is 1mm.

• Undo the cable-fixing bolt with an Allen keyand pull the cable through until the 1mm gap isachieved. Then tighten the cable-fixing bolt.

4

Toolbox

� Full set of Allen keys or Allen key multi-tool � Cross-head screwdriver � Cable puller (optional)

1 2 3 4 5

6

Brake padBrake shoe

Cable-fixingbolt

SpacersV-brake arm

Cradle

Springclip

Pivotbolt

Parts of a V-brake

Page 121: Bicycle Repair Manual

V-brake

Press the brake arms together. If they arenot vertical when the pads touch the rim,

rearrange the spacers either side of the pads untilthey are vertical.

• Release the brakes by unhooking the cable-guide tube from the cradle. Do this when youremove the wheel with correctly adjusted V-brakes.

2

Use a cross-head screwdriver to tighten or loosen the centring screw on each brake

arm. The aim is to make both arms move an equaldistance before the pad touches the rim when youapply the brake lever.

• The tension on each screw should ideally beeven, since there is an equal number of spacers on either side of the brake arm.

5 Screw out the barrel adjuster on thebrake lever to reduce brake travel and

make the brakes feel more responsive.

• Screw the adjuster outwards to reduce braketravel and create firmer braking. This technique isquick and easy to perform, and is especially usefulfor riding in the wet when brake pads can weardown rapidly.

6

Undo the brake-pad fixing bolt, removethe pad and shoe assembly, and swap the

spacers around.

• Check the pads. If they are worn, remove thepad-retaining clip, push the old pad from theshoe, and replace it with a new one.

• Line up the pads so that they hit the rim withtheir entire braking surface, and are parallel to it.Then tighten the fixing bolts.

3

121

Page 122: Bicycle Repair Manual

STEP LOCATOR

ADJUSTING YOUR BRAKES • RIM BRAKES122

Cantilever brakeCantilever brakes work with the brake levers that fit dropped handlebars, whereasV-brakes do not. This is why touring andcyclo-cross bikes are fitted with cantilevers.Cantilevers were the predecessors of V-brakes, so they may also be fitted to older mountain and hybrid bikes.

Keep cantilever brakes running smoothlyby regularly checking the pads for wear andadjusting the pad alignment and brake travel.

The cable of the cantilever brake shownin these steps is clamped to one brake armand the straddle wire running off it attachesto the other arm. On some older cantileverbrakes, the brake cable is attached to astraddle. This hooks the straddle wire thattransfers the cable’s pull to both brake armsand needs regular adjustment (see Step 1Adjusting a BMX U-brake, pp.124–25).

Adjusting a cantilever brake

Disconnect the straddle wire by pushingthe cantilever arm to which it is attached

towards the wheel with one hand. At the sametime, unhook the nipple on the straddle with theother hand.

• Undo the pivot bolts that attach the cantileverarms to the frame bosses.

• Remove the cantilever arms.

1

Angle the pads so that the front of eachpad hits the rim before the rear when the

brakes are applied – this is called “toe in”.

• Loosen the pad-fixing bolt and place a cosmeticemery board between the rear of the pad and therim. Apply the brakes and then tighten the bolt.Release the brakes and remove the emery board.Ideally, the front of the pad should be 1mm fromthe rim and the rear 2mm.

4

Toolbox

� 5mm Allen key � Grease gun (optional)� Grease

Parts of a cantilever brake

1 2 3 4 5

Cantilever arm

SpacersBrake pad Allen nut

Brake padBrake shoe

Cable-clamp bolt

1 mm

2 mm

Springclip

Page 123: Bicycle Repair Manual

Cantilever brake 123

Clean the exposed frame bosses with acloth soaked in degreaser, then lubricate

with a light grease, not a heavy-duty industrialgrease. Use a grease gun if you have one.

• Bolt both arms back on to the bosses, makingsure that the stopper pins are inserted into thesame hole on each boss.

• Replace the pivot bolts and then tighten themto hold the brake arms to the bosses.

2

Undo the brake-cableclamp to achieve the

proper spacing from the padto the rim.

• Pull the cable through theclamp until the front of eachbrake pad is 1mm from therim. Tighten the clamp bolt.

• Pull the brake lever to seeif both brake arms contactthe rim simultaneously. If theydo not, screw the centringscrews in or out on each armuntil they do.

5

Check the pads. If one is worn or badlyaligned, undo the pad-fixing bolt with an

Allen key and remove the pad/shoe assembly.

• Remove the spring clip from the brake shoe andslide out the worn pad. Slide in a new pad andreplace the spring clip.

• Return the assembly to the brake arm, line upthe pad so that its entire surface contacts the rim,and is parallel with it, then tighten the bolt.

3

Page 124: Bicycle Repair Manual

Use an Allen keyto adjust the

centring screw on eachbrake arm if the padsdo not contact the rim at the same time.Screw in to move thepad away from the rim.

STEP LOCATOR

123

ADJUSTING YOUR BRAKES • RIM BRAKES

Alternative brake designsTwo alternative brake designs are commonlyfitted to some new bikes. These are the side-pull calliper brakes used on children’sbikes and the U-brakes fitted on BMX bikes.Side-pulls work in much the same way ascallipers (see pp.118–19 ), while U-brakesresemble cantilevers (see pp.122–23).

Before buying replacement cables foreither of these types of brake, first check the kind of nipple that is presently used on the bike in question. Some levers onchildren’s bikes and older bikes require pear nipples, while other levers need barrelnipples. When a new cable is fitted to a side-pull calliper brake, leave the barreladjuster at the halfway point of its range.

Adjusting a side-pull calliper brake

Loosen the cable-clamp bolt and pull thecable through until the brake pads are

closer to the rim. This compensates for pad wear.

• Screw in the barrel adjuster to move the padsaway or screw it out to move them closer.

• Replace pads that are worn below half theirdepth by undoing the pad bolt and fitting a newpad or shoe unit in their place.

1

Undo thestraddle clamp

bolt and pull the brakecable through thestraddle with long-nosed pliers to takeup the pad wear. Then tighten the nut.

1 2

Toolbox

� Allen key multi-tool � Long-nosed pliers� Spanners

Parts of a side-pull brake and a U-brake

Brakearms

Centringscrew

Straddle-wire seat

123

124

Pivot bolts

Brakepads

Straddle-clamp

bolt

Adjusting a BMX U-brake

Pivot nut

Brakepad Brake-pad bolt

Barrel adjuster

Cable-clampbolt

Brakearms

BMX U-brake

Side-pull calliper brake

Brake-pad bolt

Page 125: Bicycle Repair Manual

Alternative brake designs

Centre the brakes if one brake pad iscontacting the rim before the other.

• Undo the brake’s pivot nut that holds it inplace and is located behind the fork crown.

• Hold the calliper so that both pads are an equaldistance from the rim and tighten the pivot nut.

2 Undo the pad bolts, line up the pads andtighten the bolt so that the brake pads

contact the rim directly in line with it. Do thiswhen you replace worn pads, too.

• Inspect the pads regularly. If you find anyridges on them, replace the pads (see Step 1) and then line them up as described above, so that the whole of their surface contacts the rim.

3

125

Line up or replace pads in the same wayas calliper brakes (see pp.118–19). Replace

the brake pads by removing the pad bolts andfitting new pad and shoe units.

• To disconnect the brake, pinch thebrake arms together and unhookthe straddle from thestraddle wire. Toreconnect, reverse this procedure.

3

Page 126: Bicycle Repair Manual

ADJUSTING YOUR BRAKES • HUB-MOUNTED BRAKES126

HUB-MOUNTED BRAKESHub-mounted brakes stop a bike by slowing down the speed of the hub.Regularly check disc brake pads for wear and alignment, replacing themwhen they are worn. Regularly check and replace the cables on cablediscs and hub brakes. Examine the hoses of hydraulic brakes for leaks.

How they workHub-mounted brakes are activated by the pull of a lever on acable, which causes pads to contact a braking surface. Springspush the pads away when the lever is released. In disc brakes,the pads act on discs attached to the hub.

In roller and coaster brakes, the pads act on a brakingsurface inside the hub. The action of the pads on the surfacethen slows down the hub and therefore the wheel. In hydraulicbrakes, the lever’s action pushes fluid through a hose; this fluidpushes the brake pads in the calliper into action. Of all the hub-mounted brakes, hydraulic disc brakes offer a rider the best control over the braking forces that can be applied.

Working in all weathersAn advantage of hubbrakes over rim brakes isthat their performance is largely unaffected byadverse riding conditions.

When the rider pulls the brake lever, the hydraulic fluid in the hosepushes on the pistons in thecalliper. These pistons in turncause the brake pad on eachside of the disc to contactthe disc and to slow therotation of the wheel.When the riderreleases the brakelever, the pressureof the fluid in thehose decreases,allowing the springs(not visible) in thecalliper to push thebrake pads apart.

DiscSlows down the hub of thewheel under pressure from

the brake pads

CalliperContainspistons andtwo brakepads

Brake padContactsthe discunderpressurefrom thefluid

HoseContainsfluid

HYDRAULIC DISC BRAKE ANATOMY

Page 127: Bicycle Repair Manual

How they work

HYDRAULIC BRAKE LEVER

Brake hoses are connected to a reservoir ofbrake fluid on each brake lever. The fluidfills the hoses all the way to the calliper onthe wheel. Pulling the brake lever operatesa piston in the reservoir, which pushes the fluid down the hose and, as a result,activates the calliper pistons.

CalliperHouses thebrakingmechanism

DiscSlows downthe wheel

Brake leverCompressesthe brakefluid

HoseCarries the brake

fluid from the leverto the calliper

127

Page 128: Bicycle Repair Manual

STEP LOCATOR

12

ADJUSTING YOUR BRAKES • HUB-MOUNTED BRAKES128

Cable disc brakeCable disc brakes work well in all conditions.Even so, check the brake cables regularly for signs of fraying and keep them welllubricated. If the brakes do not releasequickly when you let go of the brake lever,they need lubricating. Check brake travel,too, since excessive travel can mean that the brake pads are worn.

When you examine old brake pads, lookat the way they are wearing. If they havedeveloped a ridge, or the wear is in any wayuneven, the calliper may need to be realigned.

When lubricating your bike, make surethat the lubricant does not fall on or touchthe brake discs or pads. Do not even touchthe disc or pad faces, because the greasefrom your fingers can easily affect theirperformance. Always clean the discs withmethylated spirits.

Adjusting cable travel

Loosen the cable-clamp bolt on thecalliper and pull through enough cable,

with pliers or a cable-pulling tool, to take up any slack in the cable.

• Tighten the clamp bolt. This will reduce thetravel on the brakes and is a necessary adjustmentif the brake levers need pulling a long way beforethe brakes work.

1

Replace the pads if the brakes are still notworking effectively or if they are worn.

• Remove the spring clip with long-nosed pliersand loosen the pad-retaining bolt that holds themin the calliper. Take care not to damage the clips.The pads should now drop out.

1Toolbox

� Allen key multi-tool � Long-nosed pliers� Cable pullers (optional)

Parts of a cable disc brake (front)

1 2 3

Replacing pads

Cableouter

Brakecable

Brakecalliper

Brake disc

Hub

Page 129: Bicycle Repair Manual

Cable disc brake 129

Screw out the barrel adjuster to reducebrake travel. The adjuster is just above

where the cable outer sits on the calliper body.

• Loosen the fixing clamp to remove the old cableif a new cable is needed. Insert the new cable intothe brake lever (see pp.116–17) and follow Steps 1and 2 with the new cable.

• Lubricate the new cable before you fit it.

2

Insert the new brakepads and secure them

with the Allen bolt and thespring clip.

• Clean your hands beforehandling brake pads asgrease reduces the pads’ability to operate.

• Choose replacement padsthat are specific to themanufacturer of the brakesfitted on the bike. Pads madefrom different compoundsmight be worth investigatingif you want to alter theperformance of your brakes.

2

Align the callipers with the discs using theadjustment bolts. Undo these bolts, align

the calliper so that its sides are parallel with thedisc, and then tighten.

• Align brakes that are not equipped with thisadjustment facility by using spacers to pack outthe calliper-fixing bolts.

3

Page 130: Bicycle Repair Manual

STEP LOCATOR

ADJUSTING YOUR BRAKES • HUB-MOUNTED BRAKES

Hydraulic discbrake IHydraulic disc brakes are more powerful than cable disc brakes, and once correctlyinstalled, will require less maintenance. Abike that has disc-brake mountings on theframe and fork will be suitable for fitting adisc-brake system to.

Cable disc brakes can work with rim-brakelevers but their performance falls fractionallyshort of hydraulic systems. These work bycompressing a fluid rather than pulling acable. Compatible hydraulic brake levers willneed to be fitted to the handlebar and brakehoses that hold the brake fluid. Disc-specifichubs will also be required.

There is no need to fasten the front hoseto the fork. To direct and keep the rear hosein place, use an adaptor kit to let the frame’scable guides take hoses, because the cablehole in a standard cable guide is too small.

Installing a hydraulicdisc-brake system

Fit the calliper using the Allen bolts andwashers provided.

• Swap the washers around to pack out eachcalliper in order to line it up with the disc.

• Apply a thread-locking compound to the threads,then fix the disc to the hub using the disc bolts.

1

Toolbox

� Allen key multi-tool � Spanner � Stanley knife � Thread-locking compound � Flat screwdriver

Parts of a hydraulic disc brake

3456

71 2

130

Calliper

Disc

Wheelquick

release

Hose

Disc bolt

Page 131: Bicycle Repair Manual

Hydraulic disc brake I

Cut the hose of thehydraulic system if it is

too long by following Steps 3–7.

• Take out the brake pads (seepp.128–29 ) first and replacethem with a spacer. The calliperused here is a demonstrationmodel with no hose attached.

2

Carefully cut off excesscable from the detached

end of the hose with a sharpknife. Keep the olive and theshroud on the part of the hosethat you will be reconnecting.

5

Join the hose to thebrake lever by inserting

it on to the lever joint. Push ithome firmly, but not too hardas this can split the hose.

• Hold the hose upwards asyou work to keep brake fluidloss to a minimum.

6 Squeeze the olive on tothe hose at the lever joint

to make a good seal.

• Screw the shroud on to thethread of the lever joint.

• Bleed the disc-brake system(see pp.132–33).

7

Move the brass olivealong the hose and out

of the way.

• Prise the hose off the brakelever joint with a flat screwdriver,but be careful not to damagethe lever joint. At the sametime, gently pull on the hose to detach it.

4Mount the brake leveron to the handlebar and

secure with the clamp bolts.

• Unscrew the aluminiumshroud located where the hosejoins the brake lever and moveit out of the way. Prise open the brass olive beneath with aflat screwdriver.

3

131

Page 132: Bicycle Repair Manual

132

Draining and replacing brake fluid

Remove the wheels from the bike toreduce the chance of brake fluid falling

on the brake discs.

• Place a spacer in the calliper between the brake pads (see Step 2, p.131).

• Take off the brake fluid reservoir cover on thebrake lever with an Allen key. Be careful not to letany of the brake fluid touch your hands.

1

Repeat Step 4, filling up the reservoir untilthere are no more air bubbles flowing

through the clear tube when you squeeze thebrake lever. You will probably have to repeat thisstep four or five times before the bubbles in thetube completely disappear.

• Close the bleed nipple once the tube is bubble-free and the reservoir is full.

5Angle the bike so that the reservoir islevel, open the bleed nipple and fill the

reservoir with brake fluid. Pour with a smooth,constant stream to minimize air bubbles.

• Squeeze the brake lever all the way to thehandlebar and hold it. Close the bleed nipple.

• Never mix brake fluids. Mineral oil or DOT 4fluids cannot be interchanged.

4

Toolbox

� Allen key multi-tool � 10mm spanner � Length of clear hose

25

1346

Hydraulic discbrake IIIf you are pulling hard on the brake leverswithout much effect on the discs, or if youare pulling the levers several times to makethe brakes work, you need to bleed air fromthe system. The following steps will also helpif you have cut hoses to fit while installing ahydraulic system, had a leak in the system, orhave fitted a new hose.

ADJUSTING YOUR BRAKES • HUB-MOUNTED BRAKES

Page 133: Bicycle Repair Manual

Hydraulic disc brake II 133

Open the bleed nipple on the calliper witha 10mm spanner.

• Slide one end of a short length of clear tube on to the bleed nipple.

• Put the other end of the tube into a plasticcontainer that is big enough to collect the oldbrake fluid.

2

Replace the cover ofthe brake fluid reservoir

but be careful not to displaceany brake fluid.

• Refit your wheels and pumpthe brake lever a few times tocentre the brake pads.

• Go for a flat test ride. Ifyour brakes are not performingas they should there may stillbe air in the system. RepeatStep 4 and make sure thateverything is tight.

6

Pull the brake lever all the way back tothe handlebar to remove some brake fluid.

• Tighten the bleed nipple.

• Make sure that all tools are to hand since thenext steps require you to be organized.

• Cover the surface below where you are workingsince brake fluids can be corrosive. Use disposablemechanics gloves to protect your hands.

3

Page 134: Bicycle Repair Manual

ADJUSTING YOUR BRAKES • HUB-MOUNTED BRAKES

Roller-brake cableAll brake cables wear out, no matter howmuch time is spent maintaining them. Cablesfor roller brakes – sometimes called drumbrakes – are no different. If the bike isequipped with roller brakes, the steps in thissequence show how to replace a cable whenit is frayed or worn out. However, lubricatingthe brakes and replacing the internal partsare occasional jobs that are best left to theexperts at a good bike shop.

If the rear inner tube is punctured, or it isnecessary to take off the back tyre to replaceit, you need to know how to disconnect therear brake in order to remove the back wheel.At the same time, you should know how toreconnect and adjust the brake after replacingthe wheel. Once this is a familiar routine, itwill also be possible to adjust the rollerbrakes for brake pad wear from time to time.

Replacing a roller-brake cable

Push the brake-arm cradle towards thefront of the bike. This takes the tension

from the cable so that you can unhook the cable-clamp bolt from the cradle and remove the old cable.

• Screw the barrel adjuster on the brake arm inor out to about half of its extent.

• Remove the wheel at this point if you need toreplace the tyre or inner tube.

1

Tighten the cable-clamp bolt whilesqueezing the cable slightly, as your helper

keeps up the forward pull on the brake-arm cradle.

4

Toolbox

� Spanners � Long-nosed pliers

Parts of a roller brake

Brakebody

Wheelaxle nut

Brakearm

Cable-clampbolt

CableCableguide

Barreladjuster

5

134

STEP LOCATOR

1 2 3 4 6

Page 135: Bicycle Repair Manual

Roller-brake cable

Thread the greased cable through thebrake lever, then through the outer.

• Dribble a little oil into the outer.

• Make sure that the outer is firmly located inthe lever, then thread the cable through the barreladjuster and seat the outer firmly into it.

• Thread the cable through the cable-clamp bolt.

2

Pull the brake lever hard repeatedly (tentimes) to bed in the brakes. The brakes may

be a little tight as if they are being applied gently,even when there is no pressure on the lever.

• Keep about 15mm (2⁄5in) of play in the brakelever before the brakes begin to bite.

5 Screw in the barrel adjuster a few turnsuntil you achieve the 15mm (2⁄5in) of play in

the brake lever.

• Pull in the lever after each turn in the adjusterto check when the brakes begin to bite.

6

Pull the cable backwards with the long-nosed pliers while you push the brake-arm

cradle forwards and hook the clamp bolt into it.

• Bend the cable slightly behind the clamp boltand ask someone to push the brake-arm cradleforwards. Use your free hand to tighten up thebolt so the cable is nipped in place.

3

135

Page 136: Bicycle Repair Manual

ADJUSTING YOUR BRAKES • HUB-MOUNTED BRAKES

Coaster brakeCoaster, or back pedal, brakes are often fittedto children’s bikes. They work, not by pullinga brake lever, but by the rider pedallingbackwards. Their efficiency depends on thebike’s chain having a very small amount ofslack – about 3mm (1⁄8in) up and down is all that is allowed, otherwise the system does not work.

Mending a puncture or fitting a new tyremeans disengaging the brakes and removingthe rear wheel. This involves disconnectingthe brake arm and putting the wheel backwith correct chain tension. The job may betime-consuming but it is very important todo it properly. Use a workstand or simplyturn the bike upside down and rest it on the handlebar and saddle.

If the rear wheel is removed during a ride because of a puncture, let the hub cool down for a few minutes before starting. The heat comes from the action of the brakepads on the internal braking surface.

Detach the brake-arm clip from the brakearm by removing the clip bolt. When you

reconnect the brake arm, make sure that this bolt is tight, because the brake arm acts as acounter-lever for the brake to push against.

• Hold the nut behind the arm with a spanner,while unscrewing the bolt.

1

Push the wheel forwards and remove itfrom the drop-outs.

• Note the non-turn washer on the hub axle. This either screws on to the axle or sits on aflattened part of it, where its flattened profile or tab prevents the axle turning when the axlenuts are being tightened or loosened.

3

Toolbox

� Spanners � Screwdriver

136

STEP LOCATOR

1 2 3 4 5

Setting up a coaster-brake wheel

Parts of a coaster brake

Hub

Gearsatellite(otherside)

Drop-out

Brake arm

Page 137: Bicycle Repair Manual

Coaster brake

Loosen the hub of thecoaster brake with two

spanners of the correct size. The hub is secured in the framedrop-outs by two axle nuts, oneon each end of the hub axle.

• Undo the axle nuts at thesame time. When you removethem the wheel comes free from the frame.

2

Lift off the gear satellite as the axle clearsthe drop-outs. This connects the gear shifter

to the gear mechanism through the control cableand butts up against the hub.

• Lift the chain off the sprocket to completelyfree the wheel.

• Lift the chain back on to the sprocket andreplace the satellite before returning the wheel.

4 Turn the axle so that the flats or tab of thenon-turn washer fits into the drop-outs,

then replace the axle nuts.

• Pull the wheel right back, hold it straight andtighten the right axle nut, then the left one.

• Check the chain tension. If it is more than 3mm(1⁄8in) up or down, loosen the axle nuts, pull thewheel back and tighten the axle nuts again.Reconnect the brake arm by reversing Step 1.

5

137

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6

Page 139: Bicycle Repair Manual

TUNING YOURSuspension technology

has revolutionized

off-road riding. Accurate

adjustment of the front

fork and the rear shock

allows uneven terrain to

be tackled safely and

confidently.

SUSPEN

SION

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TUNING YOUR SUSPENSION • SUSPENSION FORKS

SUSPENSION FORKSA suspension fork softens the blow of a bump on the road or trail. The fork must be checked for wear and lubricated regularly. The oil and springs should be changed either when they wear or toalter the characteristics of the fork.

How they workThe suspension fork on the front wheel absorbs the energy of a bump and prevents the force fromreaching the rider. The fork’s main spring, whichcan be trapped air or a metal coil, is compressed as the sliders move up the stanchions. Compressionends when the spring has absorbed the shock of thebump. At this point, the spring pushes the slidersback and the fork rebounds. Damping controls the speed of compression and rebound, usually by absorbing some of the energy of the bump with an air or oil damping mechanism. This createsfriction, which slows down the fork’s movements.

FRONT FORK COMPRESSION

Bunnyhopping gives a graphic demonstration of compression and rebound.As the rider picks up the front of the bike to clear the log, the fork reboundsbecause the rider’s weight has been taken off the spring. On landing, the forkcompresses as the spring absorbs the shock of the bike and rider landing.

Pulling the handlebar upwards andmoving the body backwards lifts thefront wheel so the front fork rebounds.

Landing on the ground returns therider’s weight to the bike’s frame andcompresses the front fork.

Rebound Compression

140

Reacting to bumpsDamping should prevent the fork fromreaching the limits ofits travel, but the forkshould still be reactiveenough to cope withevery bump.

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How they work

When a bump pushes up the sliders on this fork, a pistonmoves up the left stanchion, compressing the air. Once thebump has been absorbed, the air pushes the piston back andthe fork rebounds. The damping mechanism in the right stanchion, which is full of oil, also moves up and down withthe bump, controlling the speed of compression and rebound.

AIR/OIL FORK

Fork crownTurns the fork

Brake archConnects the

two sliders

Slider Moves up and

down on thestanchion

Dampingmechanism

Moves upand downwith slider

PistonMoves upand down

in responseto bumps

Oil chamberContains oil

SealKeeps dirt out

of fork’sinterior

Rightstanchion

Contains thedamping

mechanism

141

AirchamberContains

air

Shaft boltFastensshaft to

slider

LeftstanchionContains

the springmechanismand piston

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STEP LOCATOR

TUNING YOUR SUSPENSION • SUSPENSION FORKS142

Front suspensionA suspension fork works best if it has beenset up to accommodate the rider’s weight.When you sit on your bike, the amount thefork depresses, as the slider moves down thestanchion, is called the sag. As you ride, sagallows the fork to extend into the hollows inthe ground, giving a smooth ride. To set theamount of sag, you can increase or decreasethe amount of pre-load in the fork.

Damping controls the speed at which afork works. To find out if a fork is workingtoo fast, lean on the handlebar, then quicklylift up the front of the bike. If the suspensionfork bangs back to its limit, its action is tooquick and its rebound damping needs to beincreased. Adjust the damping still furtherafter a few rides. The best set-up will see the fork absorb a hit and rebound quicklyenough to be ready for the next.

Setting sag

Put a tie-wrap around the stanchion of theunloaded fork and next to the top of the

slider. Ideally, the sag should be about 25 per centof its available travel, though cross-country ridersoften prefer less and downhillers more.

1

Get off the bike and carefully measure thedistance between the tie-wrap and the top

of the slider.

• Express this measurement as a proportion ofthe fork’s available travel. If the distance is 25mm(1in) on an 80mm (31⁄5in) fork, the proportion is32 per cent. Check the owner’s manual to find outthe available travel of your bike.

3

Toolbox

� Shock pump � Tie-wrap � Tape measure

Parts of a suspension fork

1 3 4

Steerer

Air valve

Stanchion

Fork brace

Brake boss

Slider

Drop-out

Crown

1

2

1

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Front suspension 143

Fine-tuning the fork

Sit on the bike, wearing your normalcycling clothes.

• Place both feet on the pedals. Either asksomeone to hold you upright on the bike or leanyour elbow against a wall. The slider will travel upthe stanchion, pushing the tie-wrap with it.

2 Fine-tune the damping on some forks withan adjuster at the bottom of one of the

fork legs. The two air chambers in this fork enablefurther refinements to damping to be made.

• Pump air into the bottom chamber with ashock pump to change the spring characteristics.

• Change the size of a valve on the air piston tocontrol air flow between chambers. This flow iscalled air-damping.

1

Make damping adjustments on some typesof fork while riding the bike. The controls

for these on-the-fly adjusters are usually marked“faster” and “slower” to indicate which directionto turn them in. It is also possible to lockout someforks. This means that you can stop their action ifyou are riding over a very smooth surface and donot need suspension.

1Increase the air in the chamber with ashock pump if the proportion of available

travel is greater than 25 per cent.

• Increase the spring pre-load with a coil/oilsystem (there is usually a dial at the top of thefork leg) or fit stronger springs.

• Release air, reduce the pre-load or fit lightersprings if the proportion is less than 25 per cent.

4

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TUNING YOUR SUSPENSION • SUSPENSION FORKS

Coil/oil forkIf the sag has been set up correctly (seepp.142–43) but the coil/oil fork keepsbottoming out – the fork reaches the fullextent of its travel but the spring cannotcompress any more – it will be necessary tofit heavier-duty springs. Conversely, if thefork only reacts to the bigger lumps andbumps, lighter springs should be fitted.

The method of changing springs is similar in most coil/oil forks, but check themanufacturer’s manual to find the featuresof the fork on the bike in question. It maynot be necessary to remove the fork leg from the fork crown; or a spring in both legs of the fork may need replacing; or one leg may incorporate the spring, whilethe other has the damping mechanism.

Setting up a coil/oil fork

Remove the circlip from around therebound adjuster of the fork by prising it

off with a flat screwdriver. Be very careful. Do notdig your screwdriver too far under the circlip, butput it far enough under so that it does not slip.Keep your fingers away from the screwdriver toavoid injuring yourself if it slips.

1

Drop the new spring into the fork leg.Make sure that it sits properly in the fork

leg, then replace the top cap.

• Screw the top cap in with your fingers, thentighten it with a spanner.

4

Toolbox

� Spanner � Allen key multi-tool� Flat screwdriver

Parts of a coil/oil fork

144

STEP LOCATOR

1 2 3 4 5

Fork crown Top cap

Fork crown bolts

Stanchion

Slider

Fork brace

Brake boss

Drop-out

Steerer

Page 145: Bicycle Repair Manual

Coil/oil fork

Undo the retaining bolts in the fork crownso that you can drop the legs out. There are

usually four retaining bolts. Some fork crowns donot have them, in which case undo a cap bolt atthe top of the fork leg to remove the springs.

2

Put the fork legs backin the fork crown and

secure the retaining bolts.

• Follow the manufacturer’storque settings when replacingthe retaining bolts.

• Reset the sag of your forks(see pp.142–43).

5

Start to remove the top cap of the forkleg with a spanner on the spanner flats,

then unscrew the cap the rest of the way out with your fingers.

• Note how the spring is sitting in the fork leg,then lift the spring out.

3

145

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STEP LOCATOR

TUNING YOUR SUSPENSION • SUSPENSION FORKS146

Air/oil forkAir/oil suspension forks usually have shorttravel and are popular with cross-countryriders. Their spring medium is air, whichmakes them very light, and their mechanismis damped by oil.

Sometimes, they have a negative springworking in the opposite direction to themain air spring. This helps to overcome thestiction (the sticky friction between twoadjacent but motionless objects) which isinherent in air/oil suspension forks and iscaused by their very tight seals.

Changing oil is necessary from time totime, as dirt in the system starts to causeexcessive wear. If you have increased thedamping on your fork and its action is stilltoo fast, replacing the oil with a heavier one will slow them down. In the same way, lighter oil can help to speed them up.

Replacing oil

Remove the cap from the top of thestanchion without the Shrader air valve.

This is the same sort of valve that is used on cartyres. You can carry out this following sequenceof steps with the fork still in the bike, although it is easier if someone helps you.

1

Make sure that you hold the fork legsabsolutely vertical.

• Place a bowl under the fork to catch anyspillage. Carefully pour new oil into the stanchionuntil it is full and then replace the cap.

• Use a calibrated chemist’s pouring vessel toensure that you accurately measure the amountof oil, if the fork manufacturer specifies.

3

Toolbox

� Spanner � Shock pump

Parts of an air/oil suspension fork

1 2 3 4 5

Steerer

Stanchion

Brake boss

Drop-out

Air valve

Slider

Fork braceFork crown

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Air/oil fork 147

Pour out the old oilfrom the stanchion

and collect it in a plasticcup. This air/oil fork has an open-bath dampingsystem, where the dampingrod moves up and down anopen oil bath. The oil alsolubricates the rest of thesuspension system.

2

Pump air in or let air out of a fork withnegative air springs after you have replaced

the oil for one of a different viscosity.

• Adjust the damping of the fork so that it worksat the speed you require, then fine-tune its actionwith the negative spring.

• Pump air in to make the fork more active oversmall bumps. Let air out to make it less responsive.

5Put the cap back on the top of the oilstanchion and tighten it.

• Set the sag again (see pp.142–43), pumping airin or letting it out to obtain the ideal sag.

• Tighten the Schrader valve if, after setting upthe sag correctly, your fork works well at first, thenstarts to bottom out (the valve may be leaking).Use a valve key from a car maintenance shop.

4

Page 148: Bicycle Repair Manual

TUNING YOUR SUSPENSION • REAR SUSPENSION

REAR SUSPENSIONThe rear suspension absorbs the shock caused by a bump in the ground or rough terrain. A shock absorber must be keptclean and lubricated, and the bushings and frame mountschecked regularly for damage and wear.

How it worksThe shock absorber of the rear suspensionmirrors the specifications of the front fork in order to increase the rider’s control of the bike. The rear triangle of the frame,which connects the rear wheel to the shockabsorber, can move independently of the rest of the frame on bikes that are fittedwith rear suspension.

Shock absorbers, or shocks as they are alsoknown, consist of a spring medium, either acoil or trapped air, and a shaft. The shaft isusually connected to a damping mechanism,which contains oil and controls the speed ofthe shock absorber’s action.

When the back wheel hits a bump on the road ortrail, the rear triangle moves up on its pivots,compressing the spring, which absorbs the shock.

As the spring pushes back on the rear triangle ofthe frame, the shock rebounds, pushing the rearwheel back ready for the next bump.

When riding over smooth ground the rear shockabsorber is in a neutral position.

When riding over rough ground the rear shock is ina compressed position to absorb bumps.

COMPRESSION OF THE SHOCK ABSORBER

148

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How they work

AIR/OIL SHOCK ABSORBER ANATOMY

In an air/oil shock absorber, thespring mechanism is compressedair that is sealed inside an airsleeve. The damping mechanismin the shock body contains oil.When the bike hits a bump, theshock body travels up inside theair sleeve and compresses thetrapped air. Once this air springhas absorbed the energy of the bump, the shock absorberbegins to rebound and return to its original position. Theshaft, which runs from the topof the air sleeve into the shockbody, is connected to thedamping device. Oil flowingthrough holes in the deviceslows the action of the shockabsorber in compression andrebound as the shock body travels up and down.

Rear shockAbsorbs theforce of abump

Rear triangleTransmits theforce of abump to therear shock

Rear wheelMoves upand down inresponse tobumps

BushingAttaches shock to frame

149

Air valveControls airpressure in thesleeve

ReboundadjusterChanges speedof rebound

ShaftRuns intoshock body

Air sleeveContainscompressed air

Shock bodyContains thedamping device

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STEP LOCATOR

SUSPENSION • REAR SUSPENSION150

Rear suspensionA good-quality, full-suspension bike shouldbe designed with a rear shock absorber thatcomplements and works with the suspensionfork in the front. Air/oil forks are normallyaccompanied by an air/oil shock and coil/oilsystems are usually married together.

The first step in setting up a rear shock is to adjust its sag. Take into account therider’s weight, as with suspension forks (seepp.142–43), and then fine-tune its action by using damping and the shock’s otherfunctions after several rides on the bike.

One simple test to see if a rear shock isworking in tune with the front fork is topress down on the middle of the bike, whilelooking at how the fork and shock react. For general riding, each should depress about the same amount.

Add the frame mounts, to which a shockis attached, to the routine safety checks (seepp.32–3). Check the bushes that allow theshock to pivot – consult the manufacturer’sguide for instructions.

Adjusting the sag

Measure the centre-to-centre distancebetween the shock-mounting bolts with

the bike unloaded.

• Sit on the bike and ask someone to measurethis distance again.

• Express the second measurement as a proportionof the first. The figure should be between onequarter and one third.

1

Accustom yourself to riding a suspensionbike before fine-tuning the damping speed

with the rebound adjuster – if your bike has one.

• Turn the adjuster on an air/oil shock absorberbut follow instructions on the shock to find outwhich way to turn.

• Do not set it too fast because this can upsetthe handling of the bike.

3

Toolbox

� Tape measure � Shock pump

Parts of a rear suspension unit

1 2 3 4 5

BushesRebound adjuster

Shock bodyLockout lever Air sleeve

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Rear suspension 151

Let air out or pumpit in as needed on an

air/oil shock absorber.

• Take the secondmeasurement again.

• Keep adjusting the airwithin the air/oil shockabsorber until thismeasurement falls towhere you want it withinthe recommended range.

• Increase or decrease thepre-load on a coil/oil shockabsorber to achieve themeasurement you want.Remember that therecommended range is only a guide.

2

Undo the quick-release lever (if yoursystem has one) to alter the total amount

of travel available, which can range from 87mmto 112mm (31⁄2 in to 41⁄2 in). This adjustment can be particularly useful at the start of a descentwhere increased speeds will mean bigger impactsfrom any obstacles you encounter on the trail.The increased travel will help to absorb them.

4 Use the lockout mechanism, if your bikehas one, to stop the action of the suspension.

The small blue lever on the illustrated unit willswitch it on or off. Across flat ground, up a smoothclimb, or on the road, the lockout temporarilyprevents the suspension from absorbing the power you are putting into pedalling.

5

Page 152: Bicycle Repair Manual

GLOSSARY152

Glossary Terms in italic within an entryare defined under their ownheadings within the glossary.

ALLEN BOLT A threaded boltwith a hexagonal depressionin the centre of its head.

ALLEN KEY Hexagonal-shapedtool that fits Allen bolts.

BEARING A mechanism thatusually consists of a numberof ball-bearings and circularchannels, or races. It allowstwo metal surfaces to movefreely while in contact.

BLOCK Sprockets fitted to afreewheel.

BOSS Threaded metal fixtureon a bicycle frame to whichan item such as a bottle cageor a pannier rack is attached.

BOTTOM BRACKET Rotatingunit that connects the crankson either side of the bottombracket shell to each other.

BOTTOM OUT A term thatdescribes the point when a suspension fork or shockabsorber reaches the limit of its travel.

BRAKE-LEVER HOOD Thebody in which the brake lever sits, connecting it to the handlebar.

BRAKE TRAVEL The distance a brake lever moves beforethe brake pads engage thebraking surface on the rim or hub of a wheel.

CABLE TIDY A small, soft-metalcylinder that is closed at oneend and fits over the cut endsof a cable to prevent fraying.

CASSETTE Sprockets that fiton the freehub.

CHAINRING A toothed ringattached to the cranks thatdrives the chain and, in turn,the sprockets and the rearwheel of a bicycle.

CHAINSET The assembly ofchainrings and cranks.

CHAINSTAY The frame tubejoining the bottom bracketshell and rear drop-out.

CLEAT A plastic or metal platethat fits to the sole of acycling shoe and engagesinto a clipless pedal to holdthe foot on the pedal.

CLIPLESS PEDAL A pedal witha mechanism to engage thecleat on the sole of a cyclingshoe and hold it securely inplace. Called clipless becausethey replaced pedals that hadtoe clips and straps.

COG A circular metal objectwith teeth, sometimes usedas an alternative term forsprocket. It usually describesthe parts within a hub gearthat can be combined to givedifferent gear ratios.

COMPRESSION The action ofa suspension system when itabsorbs an impact from theterrain. The term refers to thecompression of the spring.

CRANK The lever that joinsthe pedals to the chainringsand transfers energy from therider’s legs into the drivetrainof the bike.

DAMPING The process thatabsorbs the energy of animpact transmitted through asuspension system. It controlsthe speed at which any formof suspension responds touneven terrain.

DERAILLEUR GEARS A systemthat shifts the chain betweensprockets on the rear wheel(rear derailleur) and betweenchainrings attached to cranks(front derailleur); it allowsmultiple gearing on bikes. See also Mech.

DOWN TUBE The frame tubethat joins the bottom-bracketshell to the head tube.

DRIVETRAIN The assembly ofpedals, chainset, chain, andsprockets that drives the bikeforwards by transmitting legpower into wheel rotation.See also Transmission.

DROP-OUT A slotted plate atthe end of the fork legs andstays, into which the axle ofa wheel is attached.

EXPANDER BOLT A bolt thatdraws up a truncated cone or triangle of metal inside ametal tube in order to wedgethe tube in place. Commonlyfound inside the stem of athreaded headset.

FREEHUB A mechanism, partof the hub, that allows therear wheel to rotate while thepedals remain stationary.

FREEWHEEL A mechanismthat does the same job as afreehub but can be screwedon or off the hub.

GEAR An expression of thechainring and sprocketcombination, linked by thechain, that propels the bike.

GEAR-SHIFTER The controlmechanism, usually on thehandlebar, used to initiategear-shifts.

GRUB SCREW A headless,threaded bolt that has a

Page 153: Bicycle Repair Manual

Glossary 153

single diameter throughoutits length.

HEADSET The bearing unitthat attaches the forks to aframe and allows them toturn. There are two varieties:threaded and threadless.

HEAD TUBE The frame tubethrough which the steerertube runs.

HEXAGONAL BOLT OR NUTA threaded bolt with ahexagonal-shaped head, or a hexagonal-shaped nut thatfits on to a threaded bolt.

HYDRAULIC A mechanical system that uses compressedfluid to move an object.

LOCKRING/LOCKNUT A ringor nut used to tighten on toa threaded object and lock it in place.

MECH Short for mechanism.Device that pushes the chainon to a larger or smallerchainring or sprocket. Seealso Derailleur gears.

NEGATIVE SPRING A devicethat works against the mainspring in a suspensionsystem. In compression, forexample, a negative springworks to extend the fork,helping to overcome theeffects of stiction.

NIPPLE The piece of metalattached to the end of acable that secures the cablein the control lever.

PLAY A term to describe anylooseness in mechanical parts.

QUICK-RELEASE MECHANISMA lever connected to a skewerthat locks or releases a component from the frame.

REBOUND A term to describethe action of a suspensionsystem after it absorbs animpact from the terrain. It refers to the extension of the system’s spring.

SEAT POST A hollow tubethat holds the saddle and isinserted into the seat tube.

SEAT STAY The frame tubejoining the bottom bracketshell and rear drop-out.

SEAT TUBE The frame tubethat holds the seat post.

SIDEWALL Part of the tyrebetween the tread and rim.

SPROCKET A cog turned bythe chain. Combined withother sprockets, it forms acassette or block.

STEERER TUBE The tube thatconnects the fork to the stemand handlebar.

STEM The component thatconnects the handlebar tothe steerer tube.

STICTION A term that combines the words staticand friction. It describes thetension between moving andstatic parts at rest, such asthe seals and stanchions in a suspension fork.

STOPPER PIN The end of acantilever or V-brake returnspring that fits into a locating hole on the bike’sbrake mounting bosses.

SUSPENSION An air/oil or acoil/oil system that absorbsthe bumps from a trail orroad. The system is eitherintegrated into the fork orconnected to the rear wheelvia a linkage.

THREADS The spiral groovescut into metal that allowseparate parts to be screwedor bolted together.

TOP TUBE The frame tubethat joins the seat tube tothe head tube.

TRANSMISSION A bike’stransmission is made up ofthose parts that transfer therider’s energy into forwardmotion – the pedals, chain,chainset and sprockets. Seealso Drivetrain.

TRAVEL A term that refers to the total distance a component moves in carryingout its purpose. For example,travel in a suspension fork isthe total distance the forkhas available to move inorder to absorb a shock.Brake travel is the distance a brake lever must be pulledbefore the brakes fully contact the braking surface.

TREAD The central part of atyre that makes contact withthe ground.

VISCOSITY A rating system foroils, which also refers to theweight. A light oil has lowviscosity and moves quickerthan a heavy oil through agiven damping mechanism.This results in a faster-actingsuspension system or reduceddamping.

WHEEL JIG A stand that holdsa wheel so that its rim runsbetween two jaws. Used intruing a wheel after replacinga broken spoke.

Page 154: Bicycle Repair Manual

Page numbers in italic indicatediagrams showing the locationof parts and components. Page numbers in bold indicateentries where the maintenanceof the part is the main subjecton the page.

Aadjuster see barrel adjuster;

high and low adjuster; reachadjustment and adjuster

air sleeve 149, 149, 150air valve 13, 106, 146air/oil fork 141, 141, 146–47,

150air/oil shock absorber 149,

149, 150Allen bolt and key 13, 25, 26,

152anatomy of a bike 12–13anti-seize compound 17, 31axle nut 104, 134axle

BMX bottom bracket 70, 76,76cartridge hub 98, 98, 102, 102cartridge-bearing bottombracket 70, 70, 72, 72hollow-axle bottom bracket70, 71, 71, 74open-bearing hub 98, 99, 99,100, 100pedal 13, 78, 78, 80, 80

Bbackpedal brake see coaster

brakeball-bearing see bearingband-on front mech 52bar-end 94

barrel adjusterbrake and brake lever 113,116, 121, 124, 134gear-shifter 48, 60rear mech 12, 54

barrel nipple 116, 116, 124barrel, chain 63, 63basic bike 10, 10–11, 14–15, 15bearing 152

BMX bottom bracket 70, 76-7, 76cartridge-bearing bottombracket 70-3, 70, 72headset 13, 88, 88, 89, 89, 93hollow-axle bottom bracket70-1, 71, 74-5, 74hub gear 56hub 98, 98, 99, 99, 100, 102,102lubricating 30pedal 78, 78, 80

bench vice 25bleeding hydraulic disc brake

132–33block, freewheel 66–7, 152BMX bike 16, 17, 17

bottom bracket 70, 76, 76–7U-brake 124, 124–25

bolt and nuttightening 24, 26see also Allen bolt and key;axle nut; cable-clamp bolt;expander bolt; hexagonal boltand nut; locknut; lockring;stem cap and stem cap bolt

boss 112, 142, 144, 146, 152bottom bracket 12, 17, 70, 152

BMX 70, 76, 76–7cartridge-bearing 70, 70, 71,72, 72–3hollow-axle 70, 71, 71, 74,74–5tools 25

bottom cup 13, 88, 88, 90, 90, 92

bracket see bottom bracketbrake arch 141brake arm 12

hub-mounted brakes134, 136rim brake 112, 112, 113, 120,124

brake boss 112, 142, 144, 146brake cable 113, 114

cable disc brake 128, 128cable tidy 26, 116calliper brake 112cantilever brake 112, 116, 122cutting outer 26drop handlebar 114–15hub-mounted brake 126lubricating 30-1regular maintenance 15, 15,17roller brake 134–35side-pull calliper brake 124split or frayed 39V-brake 112, 112, 116–17

brake fluid 126, 127, 130,132–33

brake hose 126, 126, 127, 127,130, 130, 132

brake lever hood 45, 45, 96, 114, 152

brake lever 13, 15brake travel 152, 153calliper brake 118drop handlebar 96, 114, 114,122gear-shifter combination 45, 46hub-mounted brake 126hydraulic 126, 127, 127, 130position/reach adjustment 18, 19rim brake 112, 113, 113side-pull calliper brake 124straight handlebar 94, 116, 116

INDEX154

Index

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Index 155

brake pad 12, 15, 16, 17, 38cable disc brake 126, 128–29calliper brake 118–19, 118cantilever brake 122, 122coaster brake 126hub-mounted brake 126hydraulic disc brake 126, 126rim brake 112, 112, 113roller brake 126side-pull calliper brake 125V-brake 120, 120

brake shoe 118, 120, 122brake 11, 11, 12

regular maintenance 15, 17safety check 32, 38, 39servicing timetable 34–5troubleshooting chart 36–7see also cable disc brake;calliper brake; cantileverbrake; coaster brake; hub-mounted brake;hydraulic disc brake; rimbrake; roller brake; U-brake;V-brake

braking surface 12, 112, 126braze-on front mech 52, 52bunnyhopping 140bushing 148, 149, 150, 150

Ccable-clamp bolt 112, 122,

124, 134cable clamp 44, 44, 50, 51, 54cable cutters and puller 25,

26cable disc brake 126, 128,

128–29, 130cable-guide tube 12, 112, 112cable inner 44, 45, 46, 112, 113,

116cable outer 26, 39, 44–9, 113,

116, 117, 128cable port 48cable tidy 26, 116, 152

cable 44-9 lubricating 30–1, 46regular maintenance 15, 15,17split or frayed 39see also brake cable; cableinner; cable outer; gear cable;straight handlebar brake leverand cable

calliper brake 17, 104, 112, 118,118–19side-pull calliper brake 124,124–25

calliper (hub-mounted brake)cable disc brake 128hydraulic disc brake 126, 126,127, 130

Campagnolo partcalliper brake 119hub 100shifter and cable 45, 46,46–7, 114

cantilever brake 104, 112, 116,122, 122–23

carbon fibre 17, 31carrier unit 56, 56cartridge-bearing bottom

bracket 70, 70–3, 72cartridge hub 98, 98, 102,

102–3cassette body 12, 62, 62, 66cassette 62, 66–7, 152

bike anatomy 12, 62, 66cleaning 28–9regular maintenance 17tool 25, 29, 66

chainring 38, 62, 63, 152bike anatomy 13, 15, 51, 63,68, 76

chain 62–5bike anatomy 13, 40, 62, 63coaster brake efficiency 136estimating wear 64lubricating 30, 41regular maintenance 15, 15,

chain 41

chain (continued)shifting gear 44, 50, 51tool 25, 64troubleshooting chart 36–7

chainset 62, 63, 68, 68–9, 76,152

chainstay 12, 152children's bike

coaster brake 126, 136,136–37setting up 20–1side-pull calliper brake 124,124–25

cleaning and degreasing 28–9,30

cleat-release mechanism, pedal 80, 82, 82, 83

cleat, pedal 78, 82, 84, 84–5,152

clipless pedal 41, 78, 82, 82–3,83, 84, 152

coaster brake 126, 136, 136–37cog 152coil/oil fork 144, 144–45, 150common problems chart 36–7commuting bike 12component see partcompression 140, 141, 148, 152cone 76, 78, 78, 99crank 152

bottom bracket 70, 70, 71chainset and drivetrain(right-hand crank) 13, 68crank-removing tool 25, 68pedal 78, 78, 80

cupBMX bottom bracket 76, 76see also bottom cup; fixedcup; free cup

Ddamping and damping

mechanism 152fork (front suspension) 140,141, 141, 142, 143, 146

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INDEX156

damping and damping mechanism (continued)

shock absorber (rear suspension) 148, 149, 149,150

danger see safetydegreasing and cleaning 28–9,

30derailleur chain 64–5derailleur gear 12, 62, 64, 98,

152regular maintenance 15, 17,see also front mech; rearmech

dirt and oil, removing 28–9, 30disc brake

cable 126, 128, 128–29, 130hydraulic 126, 126, 130,130–33

down tube 12, 152driver unit 56, 56drivetrain 10, 13, 152

see also chain; chainring;chainset; pedal; sprocket

drop handlebar 16, 17, 94, 96–7brake cable 114–15brake lever 96, 114, 114, 122gear cable 46–7

drop-out 12, 104, 136, 142, 144,146, 152

drum brake see roller brakedry lube 30Dual Control gear shifter and

cable, 48, 49

E FErgoshift 46, 114expander bolt 152fixed cup 70, 70, 72flange, hub 62, 98, 100, 102flat pedal 78, 78folding bike 14, 15, 15foot retention mechanism 13,

78, 82–3, 82, 83see also pedal cleat

fork brace 142, 144, 146fork crown 13, 88, 88, 141, 142,

144, 146fork drop-out 12, 104, 142, 144,

146, 152fork leg 13, 144fork 10, 11, 17, 104, 140–43,

142air/oil fork 141, 141, 146–47,150coil/oil fork 144, 144-5, 150headset connection 88, 89

frame 10, 10, 12, 17, 32–3, 148free cup 70, 70, 72freehub 100, 100, 152freewheel 62, 62, 66, 66-7, 98,

152front fork see forkfront hub 98, 99, 99, 100, 102front mech 30, 41, 44, 50–3

bike anatomy 13, 15, 51front suspension see forkfront wheel removal 105

Ggear cable 44–9, 50, 58–9

cutting outer 26lubricating 30–1, 46regular maintenance 15, 15split or frayed 39Sturmey Archer 3-speed gear58, 60

gear-shifter 10–11, 44–9, 50,60, 152bike anatomy 11, 13, 45, 46,48

gear 10, 33, 39, 152see also derailleur gear; hubgear

general use bike 10, 10–11,14–15, 15

greaseapplying 30–1removing 28–9, 30servicing timetable 34–5

grease (continued)weatherproofing treatment40–1see also main entries for individual bike parts for specific lubrication instructions

Grip Shift & cable, SRAM 48, 49grip 13, 94grub screw 152

Hhandlebar stem 13, 88, 89, 89,

92handlebar tape 47, 96, 96, 97handlebar 32

adjusting on children's bike20–1see also drop handlebar; riserbar; straight handlebar

head tube 13, 88, 90, 153headset 17, 17, 40, 40, 88–93,

153hexagonal bolt and nut 153high and low adjuster, mech 50,

51, 52–3, 52, 55hose, brake 126, 126, 127, 127,

130, 130, 132hub body 98, 99, 100, 102hub flange 62, 98, 100, 102hub gear 12, 15, 15, 56, 56–61,

58, 98hub-mounted brake 126–27

see also cable disc brake;coaster brake; hydraulic discbrake; roller brake

hub 12, 13, 98, 128, 136cartridge hub 98, 98, 102,102–3open-bearing hub 98, 99, 99,100, 100–1

hybrid bike 10, 10–11, 14, 15, 15

V-brake cable replacement116–17

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Index 157

hydraulic brake lever 126, 127,127, 130

hydraulic disc brake 126, 126,130, 130–33

hydraulic system 153

Iinner tube 13, 106, 106–7, 134,

136inner see cable innerIsis bottom bracket axle 72Italian-threaded bottom

bracket 72

J Kjockey wheel 12, 50, 50, 51,

54–5, 54, 62joining pin 63, 63, 64knurled retainer 78, 80

Llever hood 45, 45, 96, 114,

152lever see brake lever; gear-

shifterlink 63, 63, 64locknut 12, 70, 76, 76, 78, 92,

99, 100 lockout mechanism 150, 151lockring 153

bottom bracket 71cartridge hub 102cassette 62headset 89hub 98

long-nosed pliers 25, 26Look road pedal 83, 83low and high adjuster, mech 50,

51, 52–3, 52, 55lubrication

applying 30–1removing 28–9, 30servicing timetable 34–5

lubrication (continued)viscosity 153weatherproofing treatments40–1see also main entries for individual bike parts for specific lubrication instructions

Mmallet 25manual 7, 24mech cage 51, 52, 52mech plate 12, 50, 50, 51mech 10, 40, 153

see also front mech; rearmech

mountain bike 12–13, 16, 17,17, 94gear cable 48–9off-road pedal 82, 82V-brake and brake cable 116,120, 122

mudguard 40, 41multi-tools 25

N negative spring 146, 153Nexus hub gear, Shimano 56,

56–61, 58nipple 153

brake lever 113, 114, 114, 116,116, 124spoke 108

nut and bolttightening 24, 26see also Allen bolt and key;axle nut; cable-clamp bolt;expander bolt; hexagonal boltand nut; locknut; lockring; stem cap and stemcap bolt

OOctalink bottom bracket axle 72,

72off-road pedal 82, 82oil

applying 30–1changing, air/oil fork 146–47removing 28–9, 30servicing timetable 34–5viscosity 153weatherproofing treatment40–1see also main entries for individual bike parts for specific lubrication instructions

open-bearing hub 98, 99, 99,100, 100–1

outer arm, front mech 51outer see cable outerowners' manual 7, 24

Pparts

bike anatomy 12–13safety check 32–3, 38–9servicing timetable 34–5technological improvements10–11, 63troubleshooting chart 36–7weatherproofing 40–1worn 38–9

pear nipple 114, 114, 124pedal axle 13, 78, 78, 80, 80pedal body 13, 78, 80pedal cleat 78, 82, 84, 84–5,

152release mechanism 80, 82, 82,83

pedal 10, 11, 17, 41, 78–83bike anatomy 13, 17, 40, 63,78

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INDEX158

pistonfork 141, 141hydraulic brake and brakelever 126, 127

pivot bolt 112, 120, 124pivot point 41, 50, 51, 51, 52,

54, 148plate spring 50, 51play 153pliers 25, 26pre-ride safety check 32–3, 38–9problem-solving chart 36–7profile 62pump 25puncture repair 106–7, 134, 136

Q Rquick-release lever and

mechanism 153calliper brake 119hub axle 98, 99, 99wheel 12, 62, 104, 104–5

quill 89, 89, 92race 70, 88, 90, 92, 99Rapidfire gear-shifter and cable

48–9reach adjustment and adjuster

18, 19, 116rear brake 12, 17rear hub 12, 98, 100rear mech 30, 41, 44, 50–1, 54–5

bike anatomy 12, 15, 50, 62rear shock absorber (rear

suspension) 17, 148–51, 149,150

rear wheel removal 104–5rebound 140, 141, 148, 149, 153rebound adjuster 149, 150release mechanism

pedal 80, 82, 82, 83quick-release see quick-release lever and mechanism

retainer, knurled 78, 80retention mechanism 13, 78,

82–3, 82, 83

retention mechanism (continued)

see also pedal cleatriding position

adult 18–19child 20–1

right-hand crank 13, 68rim brake 104, 112–13

see also calliper brake; cantilever brake; side-pullcalliper brake; U-brake; V-brake

rim 13, 39, 106, 108truing wheel 108–9

ring clamp 48ring gear 56riser bar 94, 116road bike 16, 17, 17

drop handlebar brake cable114–15

road pedal 83, 83roller bearing see bearingroller brake 126, 134, 134–35

Ssaddle 12

adjustment 18–21safety 7, 32–3, 38–9sag 142–43, 144, 150–51salt 40satellite 56, 56, 58, 60–1, 136schedule, servicing 34–5seat pin and stem 21, 31, 41seat post collar 40, 40seat post 12, 33, 153seat stay 12, 153seat tube 12, 33, 153servicing schedule 34–5setting up 18–21shaft 148, 149, 149shearing 24, 26shifters/shift lever see

gear-shifterShimano part

calliper brake 118–19

Shimano part (continued) chain 64–5, 64gear-shifter and cable 45, 45,46, 46–9, 48hub 100Nexus hub gear 56, 56–61,58Octalink bottom bracket axle72, 72road and off-road pedal 82,82, 83, 83

shock absorber (shock) 17,148–51, 149, 150

shock body 149, 149, 150shoe see brake shoe; pedal cleatside-pull calliper brake 124,

124–25sidewall 153sleeve 70, 149, 149, 150slider 13, 140, 141, 141, 142,

144, 146spanner 25, 26specialist bike 16

see also BMX; mountain bike;road

split-link chain 64, 65spoke key and spoke ruler 25spoke 13, 106, 108, 108–9spring

brake 112, 126fork 140, 144, 146negative spring 146, 153plate spring 50, 51shock absorber 148, 149

sprocket 12, 38, 51, 56, 62, 62,66, 153

square-tapered bottom bracketaxle 72

SRAM Grip Shift and cable 48, 49stanchion 140, 141, 141, 142,

144, 146star washer 88, 88steerer tube 13, 88, 88, 153steerer 89, 89, 142, 144, 146steering 13, 34–5, 36–7

see also handlebar; threaded

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Index 159

steering (continued)headset; threadless headset;top cup

stem, handlebar 13, 88, 89, 89,92, 153

stem cap and stem cap bolt 13,88, 88, 90

stiction 146, 153stopper pin 153straddle and straddle wire 122,

124straight handlebar 13, 17, 94,

94–5brake lever and cable 94, 116,116–17

Sturmey Archer 3-speed gear58, 60

suspension 153compression and rebound140, 141, 148, 149, 152, 153front suspension see forkmountain bike 16, 17negative spring 146, 153rear suspension (shock) 17,148–51, 149, 150sag 142–43, 144, 150–51servicing timetable 34–5suspension fork see forktroubleshooting chart 36–7see also damping and damping mechanism

Ttape, handlebar 47, 96, 96, 97threaded headset 88, 89, 89, 92,

92–3threaded steerer 89, 89threadless headset 88, 88, 90–1,

91thread 1533-piece and triple chainset 10, 76tightening nut and bolt 24, 26Time off-road and road pedal

82, 82, 83, 83

timetable, servicing 34–5tools and workshop 24–7top cup 13, 88, 88, 89, 89, 90,

92, 92top tube 13, 153torque gauge and setting 24transmission 34–5, 36–7, 41, 98,

153tools 25travel 50, 151, 152, 153tread 153tread wear 39triple and 3-piece chainset 10,

76troubleshooting chart 36–7truing wheel 108–9tube see chainstay; down tube;

head tube; inner tube; seatstay; steerer tube; top tube

tyre bead 13tyre 10, 11, 13, 15, 17, 106

puncture repair 106–7, 134,136regular maintenance 15safety check 32, 39

U VU-brake 124, 124–25urban commuting bike 12utility bike 14, 15, 15V-brake 17, 104, 112, 112,

116–17, 120, 120–21, 122

valve 13, 106, 146vice, bench 25viscosity 153

Wwashing and degreasing 28–9,

30weatherproofing and wet

weather 40–1wedge 88, 89, 89wet lube 30

wheel jig 108, 153wheel 10, 10, 13, 104, 104–9,

106children's bike sizes 20cleaning 28–9safety check 32, 39servicing timetable 34–5troubleshooting chart 36–7truing 108–9see also hub; rim; spoke; tyre

workshop and tools 24–7workstand 25

Page 160: Bicycle Repair Manual

ACKNOWLEDGMENTS160

Acknowledgments

PLEASE NOTE

Bicycle maintenance is potentially hazardous. Whilst the information in this book has been prepared with the reader’s personal safety in mind, thereader may help to reduce the inherent risks involved by following theseinstructions precisely. The scope of this book allows for some, but not all,

the potential hazards and risks to be explained to the reader. Therefore, thereader is advised to adopt a careful and cautious approach when following

the instructions, and if in any doubt, to refer to a good bike shop or specialist.

Author’s acknowledgments

Pip Morgan and Richard Gilbertfor their patient and diplomaticeditorial work.

Ted Kinsey for designing everything so that the writingmakes sense.

Dave Marsh of the UniversalCycle Centre for technicaladvice regarding road bikes.

Wayne Bennett of Don’t Push ItMountain Bikes for adviceregarding mountain bikes.

Tim Flooks of TF Tuned Shox foradvice regarding suspension.

Gerard Brown for his excellentpictures and Guy Andrews forgetting together the equipmentwe needed to show all theaspects of bike maintenance.

Jo Jackson and Keith andBarbara Oldfield for help whenthe author’s computer brokedown, twice.

Finally, all the bike companieswho lent their equipment forour photoshoots.

Publisher’s acknowledgments

Design: Janice English, SimonMurrell, Dawn Young

DTP Design: Gemma Casajuana

Photoshoot Art Direction:Jo Grey

Picture Research: Carolyn Clerkin

Proofreading: Lynn Bresler

Illustrations: Kevin Jones andMatthew White at Kevin JonesAssociates, Tim Loughead atPrecision Illustration Ltd.

Additional photography: Jill and Steve Behr at Stockfile

Models: Jay Black, ChrisHopkins, James Millard, SimonOon, Helen Rosser, RocheleWhyte

Cycling models: Hsu MinhChung, Jamie Newell, ClairePaginton, Hannah Reynolds,Simon Richardson, Kelli Salone,Ross Tricker, Russell Williams

Accessory, component, and bicycle suppliers:Ian Young at Moore Large for

Schwinn BMX; Caroline Griffithsat Madison for Profile, Shimano,Finish Line, Park, and Ridgeback;Ross Patterson and JonHoldcroft at ATB sales forElectra and Marin bikes; Collette Clensy at Giant Bikes;Adrian at Pashley bicycles; Sean and Stuart at Evans Cycles,Wandsworth; Cedric at LucianoCycles, Clapham; Sam atBikepark, Covent Garden;Richard at Apex Cycles,Clapham; Graham at SRAM;Shelley at Continental; Trek UK.

Picture credits

The publisher would like tothank the following for theirkind permission to reproducetheir photograph:

56-7: Stockfile/Steve Behr.

All other images © DK Images.

For further information seewww.dkimages.com