THE YZ450F-OFF! New year-model arrives; previous

year-model gets relegated to the scrap heap of obsolescence.

That’s pretty much how things work in the brutal world of 450cc motocross weaponry. The latest and greatest becomes the object of our desires, and last year’s model might as well be a chook-chaser for all the race market cares.

We all like to think we’re skeptical about the marketing spin in the brochures, and we question their lofty claims about the “all new and improved” machine. But somewhere, deep in our moto psyche – in our innate desire for a new machine that will instantly make us faster – we

can be lulled into a tacit acceptance that the shiny new model is categorically better. We get caught up in the assumption that technological advancement equates to a better ride and faster lap times. I mean, jeez, why else would a manufacturer build and release the new bike, right? Because they’ve sunk a shed-load into the thing’s development and wouldn’t mind recouping a buck or two; that’s why!

Okay, sarcasm aside, the point is this: we seem to make a lot of assumptions when instantly embracing a new-model motocrosser. Dangerous assumptions. Assumptions that are rarely challenged, because

new bikes generally aren’t tested back-to-back with the machine they’re said to supersede. Instead, they’re put up against the other new models in their class. Which is a more relevant measure of their performance, isn’t it?

True. But when we’re talking about the 2010 YZ450F – a bike that’s claimed to completely trump its predecessor, which won so many major motocross and supercross titles around the globe in 2009 – a measure of how far the new YZ450F steps it up, or doesn’t, becomes a much more relevant issue.

With that thought in mind, we approached Yamaha Australia to hunt down a fresh ’09 model so we could pit

it against their all-new fuel-injected showpony and quantify the differences between the two YZ450Fs. We flew in recently retired Pro rider and Transmoto test pilot, Cameron Taylor, to cut some back-to-back laps on the bikes. And to keep him company, we got Transmoto columnist and reigning MX Nats champ, CDR Rockstar Yamaha’s Jay Marmont, and Yamaha Australia’s press bike manager, Darren “The Enthusiast” Thompson, to join the YZ-F party. After a day’s worth of loamy laps around a mint motocross track that was meticulously prepared by the boys from Blackwell Earthmoving and Landscape Supplies, we had our answer.

Late last year, the 2010 YZ450F arrived with more fanfare than the revolutionary YZ400F did, way back in 1998. But was it warranted? Is it that much better than the ’09 bike?

We put it head-to-head with its proven predecessor to find out. ANDY WIGAN iKAPTURE IMAGES

BIKE HEAD-TO-HEAD

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BIKE HEAD-TO-HEAD

ERGOS

When two bikes look so different, chances are they’re going to feel different. And they do! You really sit down into the ’09. The seat is cushy-soft, making the bars seem taller, and the front wheel feels like it’s way out in front of you. On the 2010 bike, you sit up on it in a much more aggressive and commanding position. The seat is firmer, flatter and taller, the front wheel feels to be more underneath you, and its seat/peg/bar relationship makes the transition from sitting to standing easier. The 2010’s cockpit also makes it easier to move forward in

turns to load the front-end. The entire bike has a lighter, shorter, more compact feel about it.

When the two machines are sitting side by side, you could be mistaken for thinking the 2010 is five years more modern, not one! Aside from the new-generation engine and frame on the ’10, its new front and rear fenders, shrouds, fork protectors, number plate, fuel tank and seat design are all reminders that the ’09 YZ450F really hasn’t changed much at all since 2005, when it first appeared with an alloy frame.

Yes, the YZ-F has been way overdue for an update, but Yami certainly made a big one.

ENGINE

While the bikes were tested with standard gearing (both ran 13/49 sprocket combos), the 2010 always seemed to have an unfair advantage. Why? Aside from the fact the 13/49 combo has been too tall for the ’09 bike for several years, the 2010’s GYTR Power Tuner allowed us to quickly and easily change the bike’s entire personality. We could change from “Mud Map” to “Marmont Race Map”, or anywhere in between, in a matter of 20 seconds. So to remove the variables, we initially tested both bikes in standard trim. Then, because the

track was a loamfest with so much traction, we ran the “X Racer Map” in the 2010 – the setting that produced the most impressive dyno curve the previous night – just to see how that translated to the track.

In standard trim, the biggest difference in the two powerplants is most obvious right down low. For years, most Pros have run a shorter 50- or 51-tooth rear sprocket to help extract some low-rev punch from the ’09 bike. So with the 13/49 gearing on a grippy track, the ’09’s mellow bottom-end was really evident. You need to be much more aggressive with its throttle application, but even then,

the response just isn’t there. The ’09 is clearly down in the bottom-end and mid-range, and you need to be more active with clutch and throttle to keep it on song.

By contrast, the 2010 is fantastically responsive. It reacts quickly and crisply to all throttle inputs, and its four-valve engine produces gobs more torque. It’s much happier to be short-shifted and all that power is available at an instant’s notice. With the X Racer curve, these differences are magnified.

For a Pro-level guy, this is great news. For lesser punters on a wet track or slick bluegroove, it’ll simply create more wheelspin and fatigue. Which is

exactly why the GYTR tuner is worth its weight in gold. Plug her in, whack in a map that de-tunes that aggressive personality, and a Clubman can give

it handfuls without getting himself in trouble. And who doesn’t like that sort of versatility from one motorcycle?

The 2010 also has a noticeably

lighter clutch pull, while changes to clutch and transmission components seem to have achieved their objective: smoother and more

positive gear shifting.So our powerplant comparo didn’t

exactly leave many questions sitting on the fence. The 2010 has a lot more

torque, throttle response and power – everywhere – and comes with a tuning tool that makes it 10 engines in one. The only issue of any concern is the 2010’s fuel consumption and the fact it’s so hard to get a gauge on the fuel level because of the shape of the jet-black fuel tank. While we didn’t do a consumption test, let’s just say it always needed a bigger drink than the ’09 and, with its meager 6-litre tank, you’ve got to wonder whether it’d last a full 30-minute moto with an aggressive map in sandy conditions. Oh, that’s right, there aren’t any 30-minute motos this year at the MX Nationals!

INTAKEWith the cylinder head reversed (the inlet ports are now at the front of the engine) and the Tornado header pipe moved to where the airbox used to be, Yamaha has created a very direct path into the 44mm Keihin EFI throttle body. Hello horsepower! And with the air filter now further away from any dirt kicked up by the rear wheel, the thing stays clean for much longer.

FRAMEThe 2010 YZ450F’s all-new “Bilateral Beam” is crafted from a combination of forged, extruded and die-cast aluminium – using 26 components in all – with a centrally mounted rear shock. The thing is a work of art and claimed to create a whole lot more rigidity and improved handling. It’s been designed in unison with the all-new powerplant, which improves access for maintenance.

While much attention has been paid to the addition of EFI, the reversed head, slanted cylinder and tornado exhaust system, the most significant change to the YZ450F’s powerplant is actually its move away from the five-valve head design to an all-new four-valve configuration. Falling back in line with your competition isn’t what Yamaha is renowned for, but it was the only way they were going to get the sort of torque figures

they needed to produce a rideable 450cc motocross machine. The increase in bore (from 95mm to 97mm) means the Yamaha has gone from the smallest bore in the class to the biggest in the space of one yearl. The shorter stroke has allowed a more compact engine design (mass centralisation again), while the extra bore and EFI have handed back the top-end power that the four-valve head might have deprived it of.

TALE OF TWO ENGINES

“The 2010 has more torque, throttle response and power, and comes with a tuning tool that

gives it 10 engines in one package.”

The ’09 is plush, stable and predictable, but really lacks torque and bottom-end.

For a Pro rider, the 2010 YZ450F is virtually ready to race out of the crate.

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BIKE HEAD-TO-HEAD

BIKE SPECSRRP (incl GST, excl pre-delivery)

DISTRIBUTOR

WARRANTY

POWERPLANTCAPACITY

BORE X STROKE

COOLING

ENGINE TYPE

COMPRESSION RATIO

TRANSMISSION

FINAL GEARING

CLUTCH

FUEL CAPACITY

CARBURETTOR

SUSPENSIONFORK

SHOCK

GEOMETRYWEIGHT (fluids, no fuel)

WHEELBASE

SEAT HEIGHT

BRAKESFRONT

REAR

COMPONENTRYHANDLEBARS

FRONT TYRE (Standard)

REAR TYRE (Standard)

2009 YZ450F$11,499 (Blue); $11,599 (White)

yamaha-motor.com.au

3 months (parts only)

449.0cc

95.0 x 63.4mm

Liquid-Cooled

5-valve, DOHC single

12.3:1

5-speed

13/49

Wet, multi-disc, cable-operated

7.0 Litres

Keihin FCR MX39

Kayaba USD 48mm, twin chamber

Kayaba – 18mm shaft, 46mm piston

104.9kg

1496mm

989mm

Nissin, 250mm disc

Nissin, 245mm disc

Pro Taper aluminium, 28mm

Dunlop D742FA 80/100-21

Dunlop D756 110/90-19

2010 YZ450F$12,099 (Blue); $12,199 (White)

yamaha-motor.com.au

3 months (parts only)

449.7cc

97.0 x 60.8mm

Liquid-Cooled

4-valve, DOHC single

12.5:1

5-speed

13/49

Wet, multi-disc, cable-operated

6.0 Litres

Keihin EFI (44mm throttle body)

Kayaba USD 48mm, twin chamber

Kayaba – 16mm shaft, 50mm piston

108.1kg

1487mm

998mm

Nissin, 250mm disc

Nissin, 245mm disc

Pro Taper aluminium, 28mm

Dunlop D742FA 80/100-21

Dunlop D756 110/90-19

According to Yamaha’s Darren Thompson, “I knew from previous dyno runs we’ve done that the 2010 had more power, but this was the first time we’ve gone back-to-back against the ’09 bike on the same dyno at the same time, and I was impressed with how big a difference there is. To get more torque out of an engine, you need four valves, so it’s interesting that Yamaha has gone from five to four valves with the R1 road bike as well as the YZ-F. Five valves gives more revs, and four valves provide more torque. Then you use the fuel injection to get them to rev. Interestingly, the dyno pointed out that the

biggest power gains the new bike made over the ’09 are at high revs. That’s because the EFI lets you get the air/fuel ratio perfect at all rpm, whereas with the carb, it’s always a compromise because you’re stuck with one jet and one needle. The shorter stroke on the new bike also allows it to rev harder. So they’ve basically got more torque through the value configuration, and then found more top-end though a combination of the EFI and over-square bore and stroke.”

Dyno runs were performed for four different maps on the 2010 bike: Standard Map, Mud Map, Boyd’s Race Map and X Racer Map.

THOMMO’S TAKE...

Darren Thompson has been managing Yamaha Australia’s press fleet for five years, and has been actively involved in both bike set-up and EFI mapping options for the 2010 YZ450F since it first arrived several months back. That puts him in as good a position as anybody to offer an insight into what the new bike is like to work on. Here’s what Thommo had to say:GENERALLY: “Yamaha has worked on fastener commonality for quite a few years, so all that stuff was already fine on the ’09 model. But the chassis and engine in the new bike does seem to be designed with each other in mind. Removing the right-hand rear head bolt in the ’09 bike was a pain in the arse as you’d need to loosen the engine-mount bolts and tilt the engine to get that bolt in and out. The one downside I can see with the 2010 is that it’s a bit harder to wash. Mud tends to get baked onto the tornado section of pipe when it’s hot, so you need to take your sidecovers off and give it a bit of a scouring.”AIR FILTER: “They’re no harder to do on

the new bike; they’re just a little different. There are two extra bolts you need to undo to get to the filter, but once you establish a sequence for yourself, the 2010 takes about the same amount of time. The filter itself is a lot easier to clean and fit. It’s just a flat piece of foam, and it doesn’t get as dirty anywhere near as quickly as previous models.”OIL CHANGES: “There’s one less bolt to change the oil filter on the 2010. On the ’09 and earlier models, one of the filter

bolts is part of the oil gallery. So what can happen is that inexperienced guys can put the bolt back in with bits of swarf on it, which will then strip the thread. The bolt can then fall out and the engine can seize because it’s dumped its oil. The new bike has only two bolts, neither of which goes near the oil gallery. So that’s a big plus.”ACCESS: “Getting the now centrally-mounted shock out is a lot easier with the new bike. With no airbox in the way, there’s more room to get at it and you

don’t have to take your whole subframe off to remove it. If you do want to remove the subframe to work on your bike, you simply remove four bolts and the whole thing – tornado section of pipe included – all comes off as one unit. There’s no longer any need to drain the carby bowl after washing the bike, and the 2010’s EFI components are proving to be very reliable. Changing the mapping on the new bike is so much easier. It’s a 15-second job once you’ve plugged the GYTR controller

in. Last year, you’d have to get in there, tilt the carb to get at the pilot and mainjet, etcetera, etcetera. So the new bike is so much more maintenance-free in that respect.”MAPPING: “Aside from the fact it’s so much quicker and easier to change the new bike’s air/fuel mixture, the mapping options open up a whole range of tuning options. The advantages are amazing. It’s like bolting a pipe and a set of cams on, or taking them back out again, with one quick and easy handheld tool, all within 20 seconds. Yamaha has broken down the EFI mapping into pilot, needle and mainjet areas, so people familiar with carbs can relate. You can also play with ignition curves – for example, you can dial in more traction by adding fuel and allowing a longer burn. The GYTR controller costs $399 and is sold through Yamaha dealers. It comes with an instruction booklet that gives you some basic maps and an idea of how to make an appropriate map for your particular application. A good feature of the GYTR controller is that it won’t allow you to blow your bike up, no matter how bad your map is. We tried, and it just becomes unrideable.

INTERPRETING THE DYNO2009 YZ450F – Standard

2010 YZ450F – Standard

2010 YZ450F – Mud Map

2010 YZ450F – Boyd’s Race

2010 YZ450F – X Racer

ENGINE SPEED (RPM x 1000)

HO

RS

EP

OW

ER

56

42

28

14

49

35

21

7

4 86 105 97 11 12

HANDLING

On paper, there’s not a lot of difference between the ’09 and ’10 Kayaba fork. Both are 48mm AOSS twin-chamber units, and both run 0.47kg/mm springs. The new bike gets an extra 10mm of travel and a single-stage compression stack to help it sit up in its stroke better than the ’09, which runs a dual-stage stack. And, according to the shim specs, the 2010’s fork should have less compression damping.

All of which is why it’s difficult to explain why the 2010 YZ450F’s suspension feels significantly firmer than the 2009’s. All we could put it down to is differences in steering head angle and triple clamp offset (25 to 22mm), and changes in weight bias with the new chassis and linkage – or, more likely, a combination of them all. The shock spring goes from 5.4kg/mm to 5.6kg/mm for 2010, but with a different swingarm and linkage this year, comparisons between the two spring rates are difficult. Theory aside, here’s what the test track said…

The ’09 bike has a really plush, forgiving feel, which is fine for the average punter at

“Engine and frame on the 2010 has been built in complete harmony,

making the bike a whole lot easier to work on.”

The 2010 has a firmer front-end feel and requires less rider input to tip into turns.

The 2010 may be 3kg heavier, but it feels 10kg lighter in the air and changing direction.

S&R PRO, Penrith (02) 4732 2203

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BIKE HEAD-TO-HEAD

BIKE HEAD-TO-HEAD

THE CHAMP: JAY MARMONT 27, 80kg, 180cm

“Riding the standard ’09 bike was really interesting. I couldn’t race that bike. The ’09 offers a really plush ride and it’s stable in the choppy

stuff and through corners, but its bottom-end is certainly lacking in comparison to the ‘10. I could go out on the standard ‘10 bike and get roughly the same lap times as I do with my race bike. All we’ve really done to my race bike this year is make the suspension a little firmer – so I can push into the braking bumps and the bigger obstacles – and put the power in the right area for me. The EFI curves are tricky, but they’re so good for tuning the bike from one track to the next. Even if the track’s a bit boggy in practice, we can use a peakier setting and then mellow it out for the race when the track dries up. That’s the beauty of having the GYTR tuning tool.

“The new bike definitely turns a lot better. If you come in real hard under brakes and then want to turn off the bottom of the berm, it does that noticeably easier. Though the turn and accelerating over choppy bumps, the ‘10 has a very different character to the ’09 chassis. It’s not to say it’s better or worse in that area; it’s just something you have to work out as you spend more time on the bike. I’ve been trying things such as riding it a gear higher and shifting my weight on the bike though turns and under acceleration.“I’m finding that the ‘10 is more sensitive to subtle suspension changes. Our team was accustomed to working on what was basically the same base model for the last four or five years, so it’s still a learning process for us to get the most out of the new bike. And now that I’m racing against all these young guys who are stepping up in the Pro Open class, being able to fine-tune the 2010’s set-up – and being able to develop my riding style to suit the bike – is very important.”

average speeds. But as soon as a Pro starts to wick it up and have a go, it starts to use all of suspension travel on bumps perhaps it shouldn’t. It pushes through the stroke more on up-ramps and lands heavier.

The 2010 feels like it’s sprung significantly firmer at both ends, and is much more in line with what Pro riders in the 70 to 80kg weight range would run in their race bikes. It’s still forgiving and supple in the initial part of the stroke, but it’s the progression in the compression damping that sets it apart from the ’09. It takes bit hits and flat-landings better, and on tracks where there’s plenty of traction, the 2010 is a much more confidence-inspiring animal to push hard.

On slick or hardpack terrain, however, the ’09 delivers a more predictable and stable ride. It might not tip in to ruts or change line mid-corner as easily as the ’10, but it has a more sure-footed feel through the turn and doesn’t mind if the bloke on its back has got his weight distribution perfect or not.

Probably the biggest difference, though, is how nimble and flickable the new bike feels. Yamaha’s design mantra of mass centralisation – of concentrating inertial mass toward the centre of the machine – has really paid off. Even though our scales indicated the YZ450F put on more than 3kg since last year, it takes noticeably less effort to get the thing to turn in or change direction, and in the air you can flick it around like a 250.

MORE ONLINE...

For footage of the YZ450F head-to-head, and an insight into Team CDR Rockstar Yamaha’s experience with both bikes as a race bike platform, check out www.transmoto.com.au

PRO: CAMERON TAYLOR 36, 74kg, 173cm

“The bikes are chalk and cheese. Which doesn’t mean the ’10 is

massively better; it’s just massively different. The ’09 is slow-revving with a raked-out feel. It’s stable and forgiving, but it’s old-school. The ‘10 is more aggressive and hard-edged in every respect and it makes the old bike look and feel pretty dated. The power is right there when you need it, but it’ll also pull taller gears so you can dial the power in smoothly. That tuning tool makes it incredibly versatile, too. The ’10 is much closer to the way I’d set up my race bike, whereas the ’09 would need motor and suspension work to get it to where I’d want it. I’ve raced an ’08, ’09 and ‘10 RM450Z, and while the Suzuki feels light and flickable in the air, I can honestly say my entry speed is much better on the new Yamaha. Its geometry really seems to suit me.”

VET: DARREN THOMSON 47, 78kg, 175cm

“What I’d be telling my mates is that, if they want to line up against

Jay Marmont, they’ve got to have a ‘10 because it’s so close to his race bike (which I had a few laps on today). The good thing about the new bike is its ease of maintenance and its tunability. You can con your fat cousin into buying one and then borrow it off him on race day. Just throw in an aggressive map, and you’re away. The suspension is firmer, but it’s still forgiving on the small bumps. It feels lighter and more nimble through turns and in the air, and it’s easier to get forward on to load the front-end and make the front tyre stick. To my way of thinking, the ‘10 is a much better working platform for a race bike for a reasonably advanced rider. We haven’t done a fuel consumption test on the ‘10 yet, but it does seem to use a lot.”

“On tracks where there’s plenty of traction, the 2010 is a much

more confidence-inspiring animal to push hard, but the

’09 is more stable and predictable on slick terrain.”

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