RACING RECUMBENT TRIKE

WHAT IS A RECUMBENT TRIKE ?

A RECUMBENT BICYCLE IS A BICYCLE THAT PLACES THE RIDER IN A LAID-BACK RECLINING POSITION.

WHY USE A RECUMBENT FOR RACING?RIDERS CHOOSE THIS TYPE OF DESIGN FOR ERGONOMIC REASONS

MOST RECUMBENT MODELS ALSO HAVE AN AERODYNAMIC ADVANTAGE

DID YOU KNOW?A RECUMBENT HOLDS THE WORLD SPEED RECORD

FOR A BICYCLE, AND THEY WERE BANNED FROM RACING UNDER THE UCI IN 1934, AND NOW RACE UNDER THE BANNER OF THE HUMAN POWERED VEHICLE ASSOCIATION (HPVA).

BRIEF HISTORY • THE BANNING OF RECUMBENTS FROM BICYCLE RACING IN 1934 HAD THE

EFFECT OF PUTTING THE RECUMBENT BICYCLE DESIGN IN THE CLOSET FOR FIFTY YEARS, UNTIL IT WAS RE-DISCOVERED THERE PRIMARILY BY MIT PROFESSOR DAVID GORDON WILSON AND HIS STUDENT.

• BUT LET'S GO BACK TO SLIGHTLY BEFORE THAT UNFORTUNATE DAY IN 1934 AND LOOK AT THREE RECUMBENT PIONEERS: CHARLES MOCHET, HIS SON GEORGE MOCHET AND CYCLIST FRANCIS FAURE.

2 TYPES OF RECUMBENT TRIKES

DELTA CONFIGURATIONTADPOLE CONFIGURATION

Greenspeed Anura Delta Trike Innesenti tadpole trike

2 TYPES OF RECUMBENT TRIKES

DELTA CONFIGURATION

Greenspeed Anura Delta Trike

PROS:

• EASY TO DESIGN, CONCEPTS FOLLOW THAT OF A STANDARD BICYCLE

•LOWER COST TO MANUFACTURER, USES STANDARD BICYCLE’S COMPONENTS

CONS:

• QUICK MOMENT OF INERTIA CAUSES EXCESSIVE ROLL.

• THIS CONDITION CAN BE CORRECTED USING A LEAN STEERING MECHANISM.

• BRAKING IS COMPROMISED BY A SINGLE FRONT WHEEL WHICH MUST PROVIDE THE MAJORITY OF BRAKING FOR THE VEHICLE.

Source: http://www.hellbentcycles.com/trike_projects/Recumbent%20Trike%20Design%20Primer.pdf

2 TYPES OF RECUMBENT TRIKESTADPOLE CONFIGURATION

Innesenti tadpole trike

PROS:

• TWO WHEELS IN FRONT OFFER EXCELLENT OVERALL BRAKING

• OVERALL EXCELLENT HANDLING

CONS:

• STEERING SYSTEMS ARE MORE COMPLICATED AND REQUIRE UNIQUE PARTS

• DESIGN IS COMPLICATED AND DEPENDENT ON MANY CONTINGENCIES

Source: http://www.hellbentcycles.com/trike_projects/Recumbent%20Trike%20Design%20Primer.pdf

TADPOLE

VS.

DELTA

TADPOLE CONFIGURATION

Innesenti tadpole trike

ADVANTAGES

• TWO WHEELS IN FRONT OFFER EXCELLENT OVERALL BRAKING

• OVERALL EXCELLENT HANDLING

DISADVANTAGES

• STEERING SYSTEMS ARE MORE COMPLICATED AND REQUIRE UNIQUE PARTS

• DESIGN IS COMPLICATED AND DEPENDENT ON MANY CONTINGENCIES

BERSERKER TRIKE

THE TADPOLE ADVANTAGE

• THE TADPOLE CONFIGURATION WITH A PROPERLY CENTERED COG PROVIDES EXCELLENT TRACTION, TURNING AND BRAKING STABILITY. IT PROVIDES A LARGER TILTING RANGE, SO YOU DON'T HAVE TO GET THE TILT ANGLE EXACTLY RIGHT, AND IT CAN ALSO BE TILTED FURTHER WHILE STATIONARY WITHOUT TIPPING OVER.

RELATED PRODUCTSADVANTAGES AND DISADVANTAGES

RELATED PRODUCTSUPRIGHT BIKE

ADVANTAGES

RELATIVELY EASY TO BALANCE AT SPEEDS BELOW 2 MPH.

TRANSPORTATION IS EASY

LIGHTWEIGHT

CAPABLE OF VARIOUS STUNTS SUCH AS BUNNYHOPPING, JUMPING UP CURBS, WHEELIES, AND TRACKSTANDS.

GOOD FOR UPHILL CLIMBING

MORE VISIBLE

DISADVANTAGES

RIDER IS ADVISED TO CHANGE POSITIONS OFTEN TO AVOID SORE SPOTS. 

SADDLESORE I.E. BRUISED PERCH BONE AREA, CARPAL TUNNEL PROBLEMS I.E. SORE PALMS AND NUMB FINGERS, ALSO SORE WRISTS, ELBOWS, SHOULDERS, AND NECK, TENDER KNEES.

TOO MUCH WEIGHT PUT ON LEANING POSITION.

BACK IS NOT RELAXED

NECK STRAIN

RECUMBENT BIKE EXERCISE MACHINE

IT IS USED FOR THE BENEFIT OF PEOPLE WHO HAVE CARDIOVASCULAR PROBLEMS OR THOSE WHO ARE LESS FIT.

ADVANTAGES

WORKOUT OF GLUTEAL MUSCLE.

NO MORE SORE OR NUMB WRISTS BECAUSE PALMS NO LONGER ASSIST THE BURDEN OF THE ENTIRE BODY.

ADVANTAGES

RIDER SITS INTO THE BIKE FRAME

SEAT LOCATED ALMOST IN-LINE WITH THE PEDALS

LOW COG (CENTER OF GRAVITY) MAKING THE BIKE AND RIDER VERY STABLE

NATURAL, RECLINED POSITION WITHOUT NEED TO BEND HEAD OR BACK

NATURALLY COMFORTABLE SEAT = MORE COMFORTABLE WORKOUT

CYCLING IN A MORE NATURAL POSITION OF BODY ALIGNMENT REDUCES FATIGUE

THE “Q FACTOR"

THE Q FACTOR OF A BICYCLE IS THE DISTANCE BETWEEN THE PEDAL ATTACHMENT POINTS ON THE CRANK ARMS

SOME RECUMBENT BIKES MAY HAVE A WIDER Q FACTOR TO ALLOW FOR BRAKING MECHANISM, PULLEYS, DRIVING COMPONENTS, AND COSMETIC COVERS

A NARROWER Q FACTOR IS ERGONOMICALLY SUPERIOR BECAUSE IT CLOSELY MATCHES THE NEARLY INLINE PATTERN OF HUMAN FOOTSTEPS

ADVANTAGES

NO MORE SEAT PROBLEMS: RECLINED SEATING

NO STRESS AND WEIGHT PUT ON BY LEANING

NO SORE HANDS: ARMS NATURALLY HANGING ON THE SIDES

NO NECK PAIN

RECUMBENT BIKE

MORE ADVANTAGES

COMFORT - LONG RIDES ON AN UPRIGHT BIKE CAUSE TOO MUCH PAIN

AERODYNAMICS - MANY RECUMBENT SETUPS HAVE A SMALLER FRONTAL AREA, WHICH MAKES THE BIKE FASTER IN A HEADWIND

HEADS-UP POSITION

PROTECTION FROM ADVERSE WEATHER

PRACTICALITY

DISADVANTAGES

UNNERVING ON STEEP CLIMBS (WOBBLE FACTOR)

UNSTABLE(2 WHEELS ONLY): INCREASED CHANCE OF FALLING OVER

SLOWER CLIMB BUT FASTER DOWNHILL

MORE DISADVANTAGES

LESS STABLE AT VERY LOW SPEEDS; HARDER TO KEEP RECUMBENT IN A STRAIGHT LINE WHEN GOING UP A STEEP HILL

HARDER TO RIDE ON GRAVEL ROADS

CAN’T SHIFT BODY WEIGHT TO COMPENSATE FOR MINOR FISHTAILING OF THE WHEELS

CAN’T “FALL STANDING UP” WHEN YOU LOSE CONTROL AT LOW SPEED BECAUSE LEGS ARE HORIZONTAL

HARDER TO SEE OVER TRAFFIC DUE TO LOWER SEAT HEIGHT

2 TYPES OF STEERING ON RECUMBENT BIKES

OVER SEAT STEERING

PROS

THERE IS A PLACE FOR A REARVIEW MIRROR ON THE HANDLE BAR.

BIKERS ARE MORE USED TO THIS STEERING. ALTHOUGH IT MIGHT CAUSE WRIST SORES AND NUMBNESS OF FINGERS.

EASIER TO “WALK” YOUR BIKE.

CONS

o SLIGHTLY HARD TO USE

2 TYPES OF STEERING ON RECUMBENT BIKES

UNDER SEAT STEERING

PROS

EXTREMELY COMFORTABLE AND EASIER TO RIDE

GETTING ON AND OFF IS EASIER SINCE THERE IS NO HANDLE BAR IN THE WAY

CONS

o ALTHOUGH MOST BIKERS ARE NOT USE TO THIS POSITION

o IT HAS NO PLACE FOR REARVIEW MIRROR

UNDER SEAT STEERING

VS.

OVER SEAT STEERING

SEATING

HAMMOCK MESH

PROS

OFFERS BREATHABLE COMFORT.

LIGHTWEIGHT

CONS

o DUE TO THEIR DESIGN, A MESH BASE CAN MAKE THE BIKE DIFFICULT TO HOLD UP AT A STOP (EVEN FOR A TALL RIDER).

MOLDED SEAT

PROS

EURO MOLDED SEATS HAVE A DISTINCT LUMBAR CURVE AND ARE DESIGNED TO FOR A VERY LAID-BACK POSITION.

FOAM AND COVER OFFERS A MORE FIRM BASE TO PUSH AGAINST,

CONS

o THOUGH IT MAY BE LESS COMFORTABLE

MESH

VS.

MOLDED

WHEEL SIZE 20 INCH FRONT WHEELS

PROS

MORE MANEUVERABLE

MORE AERODYNAMIC

CONS

IT MAY FEEL WOBBLY FOR BEGINNERS

700 C OR 26 INCH REAR WHEEL

PROS

FASTER

SMOOTHER RIDES

CONS

IT DOESN’T WORK ON DELTA TRIKES WITH LONG WHEEL BASIS

TADPOLE TRIKES BRAKE

• MOST TADPOLE TRIKES USE ONLYFRONT BRAKES. A BACK BRAKE IS RARELY USED.

• FRONT BRAKING SYSTEM: DRUM, DISC

DRUM BRAKES

DISC BRAKES

TADPOLE TRIKES BRAKE

DRUM BRAKES• CLASSIFIED AS A SINGLE, LEADING

SHOE BRAKE.

• USES TWO BRAKE SHOES INSIDE A CYLINDER DRUM.

DISC BRAKES• APPLIES A SET OF FLAT PADS ON

OPPOSING SIDES OF A REVOLVING ROTOR

• THE BRAKE IS INFALLIBLE TO FADING OR MOISTURE BUILDUP.

DRUM BRAKES

ADVANTAGE• IT PROVIDES SOLID AND RELIABLE

BRAKING AND IS OPTIMIZED FOR TADPOLE TRIKE DESIGNS.

DISADVANTAGE • IS THAT A DRUM BRAKE PERFORMS

POORLY IN WET WEATHER CONDITIONS (IF MOISTURE GETS INTO THE DRUM)

• IS SUSCEPTIBLE TO HEAT FADING.

• THE SELF-ENERGIZING DRUM BRAKEACTION IS NONLINEAR AND MAY BE SLIGHTLY UNPREDICTABLE.

DISC BRAKES

ADVANTAGE• THE SELF-ENERGIZING DRUM BRAKE

ACTION IS NONLINEAR AND MAY BE SLIGHTLY UNPREDICTABLE.

• ACTION IS PROPORTIONAL AND PROVIDES SMOOTH BRAKINGEVEN DURING THE HARSHEST WEATHER CONDITIONS.

DISADVANTAGE • HEAVY COMPARED TO DRUM BRAKES.

• LIGHTER DISC BRAKES ARE AVAILABLE BUT VERY EXPENSIVE

• MOST DISC BRAKES ARE PRONE TO RUBBING AND ALSO A PERFORMANCE ROBBER

DRUM BRAKE

VS.

DISC BRAKE

SHELL

• AN AERODYNAMIC CARBON FIBER AND KEVLAR SHELL BUILT AROUND A LOW-PROFILE RECUMBENT BICYCLE.

• CAN MAKE A TOP SPEED OF 82.819 MPH

VARNA TEMPEST

• CAN HANDLE ANY KIND OF INCLEMENT WEATHER AND IT’S EQUIPPED WITH LED LIGHTS TO MAKE IT VISIBLE TO CARS AT NIGHT.

All-Weather Firefly Trike

• A SLEEK AERODYNAMIC SHELL THAT SNAPS ONTO ANY BICYCLE TO PROVIDE PROTECTION FROM THE ELEMENTS ONCE THE WEATHER TURNS FOR THE WORSE.

Capsule Shields Cyclists

• PROS:

• THE SHELL RESISTS THE OPPOSING WIND AND THUS, HELPS THE BIKE TO SAIL THROUGH WITH MAXIMUM EASE.

• THE AERODYNAMIC OUTER BODY OF THE BIKE IS CALLED THE SHELL, MADE OF STURDY CARBON FIBER, WHICH NOT ONLY ENHANCES THE VISOR OF THE BIKE, BUT ALSO HELPS IT TO RUN FASTER BY LETTING THE AIRFLOW GO SMOOTHLY.

• THIS SHELL OFFERS COMPLETE SAFETY FOR THE RIDER IN CASE OF ANY ACCIDENTS.

AEROK BICYCLE

TURNING

DELTA• LONG WHEEL BASE OF DELTA

DECREASES THE TWITCHINESS OF THE STEERING, IMPROVING HIGH SPEED CONTROL AND PRECISION

• REARWARD WEIGHT DISTRIBUTION FAVORS OVERSTEER. TEND TO SPIN OUT AND LOSE TRACTION ON LOOSE GRAVEL.

TURNING

TADPOLE• MORE STABLE THAN THE DELTA

• POSSIBILITY OF TIPPING FORWARD WHEN COMBINING TURNING AND BRAKING FORCES.

LEAN STEERING

A LEAN STEERING TRIKE IS A THREE WHEELED VEHICLE THAT STEERS BY VIRTUE OF LEANING THE RIDER'S BODY

INTO THE DESIRED DIRECTION OF THE TURN. ALTHOUGH SEVERAL VARIATIONS EXIST, THE MOST NOTABLE

IMPLEMENTATION IS WHERE THE SEAT MOVES IN RELATION TO THE FRAME CAUSING THE VEHICLE WHEELS TO

TURN OR ALTER THE WHEEL GEOMETRY. A STATIONARY HORN OR TILLER IS FIXED TO THE FRAME (THIS CAN ALSO

BE A U-BAR) ALLOWING THE RIDER TO LEAN THE SEAT LEFT OR RIGHT (THE SEAT IS LINKED TO A STEERING

MECHANISM), HENCE STEERING THE VEHICLE. SINCE THE RIDER LEANS INTO THE DIRECTION OF THE TURN,

THE CENTER OF GRAVITY IS OPTIMIZED PRODUCING A TRIKE WITH EXCELLENT LOW SPEED HANDLING. THE

CONCEPT IS SIMILAR TO STEERING A BICYCLE WITH ONE OBVIOUS EXCEPTION: THE LEANING IS LINEAR TO THE

STEERING AND NOT BY THE G FORCES APPLIED. CONSEQUENTLY, THE STEERING IN THIS IMPLEMENTATION IS

NOT OPTIMIZED FOR HIGHER SPEEDS.

TILTING

30 DEGREE TILT

PROS

POSSIBILITY OF LOW SIDE TITLTING TRIKE

CONS

o SITTING TOO LOW IS A SAFETY CONCERN

TILTING

45 DEGREE TILT

• THE BODY IS TOO HIGH, THEN I'LL NEED A REALLY WIDE TRACK TO MEET ONE OF MY MINOR DESIGN CRITERIA — THAT LEANED FULLY OVER, THE VEHICLE WILL NOT ACTUALLY TIP OVER AND FALL IF NOT MOVING. WITH NO ABILITY TO PUT MY FEET DOWN, THIS LITTLE DETAIL IS CRUCIAL. ON THE POSITIVE, IT'D MEAN A NICE HIGH LINE-OF-SIGHT. IT WOULD SEEM PRUDENT TO FIND SOMETHING IN BETWEEN.

TILTING• BY ALIGNING THE BOTTOM OF

THE BODY WITH ESSENTIALLY THE AXLE HEIGHT, I THINK I'VE FOUND THE SWEET SPOT. 40º SEEMED EASY WITH ONLY THE WHEEL PANT IN DANGER OF INTERFERENCE THIS PUTS IT ALMOST EXACTLY WHERE MY LINE-OF-SIGHT IS IN MY MINI, WHICH IS ACTUALLY VERY GOOD.

• VERY CLEAN AERODYNAMICS AND EASY ROAD GOING OVER FAIRLY SUBSTANTIAL ROAD HAZARDS.

DESIGN PARAMETERS

• FRAME DESIGN- CARBON FIBER (LIKE THE AEROK BICYCLE SHELL)

• STEERING- UNDER SEAT STEERING

• TADPOLE CONFIGURATION

• MESH SEAT

• 20 INCH FRONT WHEEL AND 700 C OR 26 INCH REAR WHEEL

• BRAKING SYSTEM- DRUM BRAKE

• TILTING

Aerok bicycle shell

DESIGN PARAMETERS

• SADDLE WIDTH- 355MM TO 406MM (TILTED UP TO 5 DEGREES AT THE FRONT)

• BACKREST ANGLE- 30 T0 40 DEGREES

LENGTH- 450 MM

• CRANK LENGTH – 160 MM (MIN=640MM, MEDIAN 790MM MAX=940MM)

• BOTTOM BRACKET TO BACK OF SEAT 800MM TO 1100 MM

• BOTTOM BRACKET CLEARANCE- 350 T0 400 MM

• BOTTOM BRACKET HEIGHT- 400 MM

• SEAT HEIGHT- 400 TO 470 MM

• LUMBAR -190 MM

• SHOULDER SUPPORT-120 MM

CONCLUSION AND SUMMARY

RECUMBENT BIKE

ONE OF THE MOST COMMON REASONS FOR USING A RECUMBENT BIKE IS COMFORT. NOT ONLY DO THEY HAVE A LARGE SEAT, BUT THE BIKES ALSO OFFER COMPLETE BACK SUPPORT. THIS ERGONOMIC ADVANTAGE IS ESPECIALLY IMPORTANT FOR PEOPLE WITH BACK OR NECK PROBLEMS. BECAUSE OF THEIR LOW CENTER OF GRAVITY, RECUMBENT BIKES ARE ALSO MORE AERODYNAMIC AND CAN PICK UP SPEED MORE EASILY.

POSITIONING

SEAT POSITIONING

• IN A RECUMBENT BIKE, YOU ADJUST THE SEAT EITHER FORWARD OR BACKWARDS, RATHER THAN UP OR DOWN LIKE AN UPRIGHT BIKE.

• THE SEAT RECLINE ALLOWS FOR ADJUSTMENTS, START AT A MID-POSITION. ACCORDING TO BACCHETTA BIKES, BEING TOO STRAIGHT OR TOO RECLINED CAN CAUSE DISCOMFORT AND PAIN FOR BEGINNER RIDERS. AN UNCOMFORTABLE SEAT POSITION CAN ALSO PUT ADDITIONAL STRESS ON YOUR KNEES AND MAKE RIDING MORE DIFFICULT.

LEG POSITIONING

• THE LEG SHOULD HAVE ONLY A VERY SMALL BEND

•  IN A RECUMBENT BIKE, THIS MEANS AN ANGLE OF JUST A FEW DEGREES. THE LEGS SHOULD NOT BEND TOO MUCH AT ANY GIVEN TIME, SINCE THIS PUTS A LOT OF PRESSURE ON THE KNEES.

KNEE POSITIONING

•  THE LEGS ARE ALWAYS EXTENDED FORWARD, THE RIDER MIGHT END UP WITH SORE KNEES AFTER RIDING A RECUMBENT BIKE.

• THE MORE YOU LEAN BACK ON YOUR SEAT, THE MORE YOU HAVE TO USE YOUR LEGS AND THE LESS PRESSURE YOU PUT ON YOUR BACK AND OTHER PARTS OF YOUR BODY. RECUMBENT BIKES ALSO REQUIRE LITTLE WRIST AND LOWER ARM STRENGTH.

STEERING POSITION

• UNDER SEAT STEERING GOES WAY BEYOND WHAT MOST RECUMBENT WILL DO FOR COMFORT.

• THERE ARE TWO TYPES OF USS, DIRECT AND INDIRECT. DIRECT IS BEST THOUGHT OF AS A HANDLE BAR MOUNTED TO THE BACK SIDE OF THE FORK AND EXTENDING BACK FAR ENOUGH TO DROP YOUR ARMS STRAIGHT DOWN BESIDE THE SEAT AND GRAB ON. A COUPLE OF THE DRAWBACKS TO THIS DESIGN ARE HAND POSITION AND INTERFERENCE WITH THE SEAT IN SHARP TURNS.

• LONG BIKES USES AN INDIRECT STEERING. INDIRECT IN THAT THE HANDLE BAR IS MOUNTED TO THE FRAME AND USES LINKAGE (IN AUTOMOTIVE TERMS, A DRAG LINK) TO CONNECT TO THE FORK

•  A COUPLE OF ADVANTAGES ARE THAT THE STEERING RATIO OR SPEED CAN BE ADJUSTABLE AND THE HANDLE BAR ROTATES ABOUT A PIVOT POINT UNDER THE SEAT. THE ENDS OF THE HANDLE BAR MOVE IN AN ARC BESIDE YOUR LEGS, WITH A MOVEMENT THAT IS ESSENTIALLY A PUSH PULL BY THE RIDER.

USS (UNDER SEAT STEERING

• ADVANTAGES

• RELAXING AND DOESN'T PUT ANY STRAIN ON THE UPPER BODY.

• BETTER SUITED TO CYCLISTS BEARING HAND, ARM OR SHOULDER INJURIES

• A GREAT WAY TO ENSURE YOUR KNEES AREN'T GETTING BASHED ON THE HANDLEBARS.

• DISADVANTAGES

• MORE COMPLICATED MECHANICALLY AND THUS REQUIRES MORE MAINTENANCE AND ADJUSTMENTS.

• FAR MORE EASILY DAMAGED IN EVEN A MINOR ACCIDENT.

• MORE UNUSUAL AND THUS CAN BE MORE DIFFICULT FOR AN INEXPERIENCED RECUMBENT CYCLISTS TO ADJUST TO.

• MORE DIFFICULT TO MANHANDLE.