My 2008 Yz 450f Review

I'm always wary of the dyno charts produced by speed equipment manufacturers. Typically, the trick is that they test a stone stock unit that hasn't been tuned or jetted or optimized in any way, then compare that to the same bike with their stuff on it that's had the whole treatment.

just got a new holeshot device and it won't work on the 08. they changed the groove at the bottom of the outer fork tube. its very narrow now.

Call it what you want, but the evolution of loud four strokes is leading to the closing of many private/public tracks and riding areas. Check out Honey Lake MX in NorCal. Larry Wosick has been served w/$250K in noise fines from one of his recent races. Do any of the 450's need to be faster and louder? Yamaha's design may not be the best, but at least they recognize the problem.

I agree that it is "Big Brother", but our sport doesn't have the "lobby" if you will, to fight the sound issue effectively. As mainstream as SX/MX is becoming, it will still never get the leverage that NASCAR/Drag Racing and even Harley's get. Remember NASCAR comes to an area 1 or 2 weeks a year and is gone. (on top of that the $ it brings to an area dampens the sound concerns) We ride our tracks/riding areas etc all the time and to the neighbors/business' etc the sound has gotten much more offensive w/the evolution of 4T's & loud aftermarket exhaust. Europe has strict db rules and it works fine and the bikes still have plenty of hp. I'd like my kids to have somewhere to ride in the future.

I AGREE WITH THE NOISE CRAP.... THINGS IN OUR COUNTRY ARE GETTING WAY TOO OUT OF HAND. TOO MANY MORONS THAT NEED TO CALM DOWN. ALL THE LAW SUITS ARE RUINING OUR RIDING AREAS. YAMAHA IS TRYING TO GOOD THING SO THAT ALL THE ******** CAN CALM DOWN. ALL I CAN SAY IS SINCE I MOVED TO WORK IN MEXICO IT SURE IS NICE TO HAVE MY OWN TRACK. HAVE RIDERS, RACES AND NOT WORRY ABOUT LAW SUITS. WWW.FREEWEBS.COM/HELLTRACK. WHO KNOWS WHERE THINGS ARE GOING TO BE LEGALLY WHEN I MOVE BACK???:foul:

i have an 06 yz450. is it even worth it to upgrade to an 08?

not in my humble opinion unless you just need a new bike.....new power charactersitics and new handling & suspension to sort out...:thumbsup:

there just is not a night and day difference in the 06-08.....I will wait for 09

I am not sure if they are just trying to sell bikes, but according to Langston and Dubach, there is a big difference between the 07 and 08, at least in terms of the way it turns.....

If you want one, buy one.

I am not sure if they are just trying to sell bikes, but according to Langston and Dubach, there is a big difference between the 07 and 08, at least in terms of the way it turns.....

If you want one, buy one.

According to me there is a huge difference in the way it turns. If your a decent racer than its a good difference. If your a weekend warrior, forget it.

I am getting the quick turn throttle so I can get to wide open quicker. Im hoping this will help a bit.

I am not sure if they are just trying to sell bikes, but according to Langston and Dubach, there is a big difference between the 07 and 08, at least in terms of the way it turns.....
According to the published information in the manual, the head angle of all three bikes is the same, but the '08 has an increase in trail that would correspond to the use of a 24mm clamp offset, rather than the 25mm used on the earlier bikes. This could be done either with the clamps, or by moving the axle back in the fork leg, as Honda has done a couple of times. Either way, it looks like Yamaha has incorporated yet another of Dr.D's recommendations into production, as he's been saying that the 24mm clamps were the way to go for the '06 for some time now.

He said the reduction in weight of the front brake caliper had a lot to do with it as well.

That is, of course, an improvement, as would be any reduction in unsprung weight, but I'd be shocked if the new caliper was 12 oz lighter than the old. It's a positive, and a contribution, but "a lot o do with it"? No. Front tires vary in weight more than that.

grey I am just telling you what he said. We were talking about whether the suspension on the 07 would fit an 08. He said it would, but you would have to use the 07 caliper and that it wouldnt be worth it because the new '08 lighter caliper is a big part of why the '08 turns better.

I surely am not going to question him when it comes to the inner workings of a Yamaha.

grey I am just telling you what he said. We were talking about whether the suspension on the 07 would fit an 08. He said it would, but you would have to use the 07 caliper and that it wouldnt be worth it because the new '08 lighter caliper is a big part of why the '08 turns better.

I surely am not going to question him when it comes to the inner workings of a Yamaha.

Ya the front brake setup is different on the 08. Surprisingly my buddy thought he was going to be able to use more of his 07 goodies on his 08 but that wasnt happening, too many little changes.

grey I am just telling you what he said. We were talking about whether the suspension on the 07 would fit an 08. He said it would, but you would have to use the 07 caliper and that it wouldnt be worth it because the new '08 lighter caliper is a big part of why the '08 turns better.

I surely am not going to question him when it comes to the inner workings of a Yamaha.

All that would be necessary in the extreme case that the '08 caliper will bolt on to neither the caliper mounting lugs of the '07 fork, or the 'C' shaped caliper sub bracket from your '07, would be to interchange the damper cartridges and springs between the two sets of forks. Since the bare fork tubes are just tubes, and contain no valving, that would effectively put your existing suspension in the '08 forks.

But Mr. Langston is a factory rider, and a company employee, when he tells you that the new, lighter caliper is a "big part" of the handling improvements made to the '08, he's reading off the company marketing sheet. Yamaha Sales is naturally touting every refinement made as a "big" thing. Refinements are refinements, and they're all good, and they all add up, but they're rarely "big" except as a part of the whole.

See for yourself. Get some peel and stick wheel weights and add 6 or 7 ounces to the bottom of one fork leg, or to your caliper. See if you can tell it's there.

All that would be necessary in the extreme case that the '08 caliper will bolt on to neither the caliper mounting lugs of the '07 fork, or the 'C' shaped caliper sub bracket from your '07, would be to interchange the damper cartridges and springs between the two sets of forks. Since the bare fork tubes are just tubes, and contain no valving, that would effectively put your existing suspension in the '08 forks.

But Mr. Langston is a factory rider, and a company employee, when he tells you that the new, lighter caliper is a "big part" of the handling improvements made to the '08, he's reading off the company marketing sheet. Yamaha Sales is naturally touting every refinement made as a "big" thing. Refinements are refinements, and they're all good, and they all add up, but they're rarely "big" except as a part of the whole.

See for yourself. Get some peel and stick wheel weights and add 6 or 7 ounces to the bottom of one fork leg, or to your caliper. See if you can tell it's there.

Took these right off the Yami web site:

New, YZ250F-style, front-brake caliper (-220 grams) and a lighter disc remove unsprung weight and provide excellent stopping power. A new axle and collar remove additional weight.

Steering head pipe and steering stem are 5mm shorter; lower forged triple steering clamp is lighter—for enhanced handling feel. Swingarm pivot stiffness is revised to complement front-end changes and further lighten and improve steering/handling.

I thought the front brake thing was BS but 220 grams is about 1/2 a pound so maybe it does something. :excuseme: And I thought I read in MXA that the steering head was lowered by 5mm not shortened and that would definitely help the front end stick.

I sold my 06 YZ450 because of the handling issues and went back to the YZ250 smoker. The 450 was my first 4 stroke and it put a bad taste in my mouth about them. :thumbsdn:

Took these right off the Yami web site:

New, YZ250F-style, front-brake caliper (-220 grams) and a lighter disc remove unsprung weight and provide excellent stopping power. A new axle and collar remove additional weight.

Steering head pipe and steering stem are 5mm shorter; lower forged triple steering clamp is lighter—for enhanced handling feel. Swingarm pivot stiffness is revised to complement front-end changes and further lighten and improve steering/handling.

I thought the front brake thing was BS but 220 grams is about 1/2 a pound so maybe it does something. :excuseme: And I thought I read in MXA that the steering head was lowered by 5mm not shortened and that would definitely help the front end stick.

1/2 pound is 8 ounces, so I was in the ball park on that. And there's no question that is does something; it reduces unsprung weight. That's an important thing because the unsprung mass, which is everything not carried by the suspension, is what the suspension must control to maintain wheel contact with the ground, and thereby, traction. The lower the unsprung mass, the easier it is to control.

Think of it this way. The ideal is that the chassis and the rider should glide along on an absolutely even, undisturbed level, completely undisturbed, while at the same time, both wheels follow every contour of the ground, regardless of how big or little, never loosing contact with it, while the rider is completely isolated from any of what the wheels are going through.

For example, when you are speeding along on the level and the front wheel encounters a bump, the wheel is driven upward by the impact. As the wheel clears the top of the bump, we want it to stay in contact with the ground, and follow the contour right back down to where it was, so the wheel's direction has to be reversed by the front suspension as soon as the upward force is gone. A heavy wheel will resist this, and tend to jump off the crest of the bump, where a lighter one will be more easily influenced to run back down the back side of the bump without transmitting as much of the suspension rebound to the chassis, and/or loosing contact with the ground.

The unsprung mass of the front end of a YZF consists of the complete wheel assembly, axle, the lower fork legs, brake caliper, the cartridge damper rods, the oil in the outer tubes, and half the weight of the springs and brake hose. Making that assembly lighter by 8 ounces in going to represent a fairly small percentage change in the total unsprung weight. Will it help? Of course. Will it be "big", not really.

What you saw in MXA is that the handlebar mounts on the '08 are 4mm taller because the top of the steering head has been lowered by 5mm. Yamaha says the steering tube was shortened by 5mm. Far from being in conflict with one another, these two pieces of information tell you exactly what was done: the bottom of the steering head is exactly where it was, and head tube is 5mm shorter, lowering the upper clamp by 5mm. As I pointed out, the head angle has not changed from '07, so this does nothing other than lighten the bike (which is inarguably good), and has no effect on steering geometry.

I sold my 06 YZ450 because of the handling issues and went back to the YZ250 smoker. The 450 was my first 4 stroke and it put a bad taste in my mouth about them. :thumbsdn:

This is where most of your problem is. Four-strokes, all of them, handle fundamentally differently from two-stroke MX bikes. As a group, thumpers all put a great deal more of the turning load on their front tires. This is compounded by the fact that 4-strokes, even the very snappy ones, have naturally less tendency to break the rear tire loose as the throttle is applied, and that tends to make them push under power, and refuse to lay down as easily as a pinger. Your objections to the handling of your '06 is more a generic objection to this trait than to the traits of a particular bike.

Grey it wasnt Langston that told me that, it was Dubach.

That all sounds like good sound thinking on your part.

As for my not liking my old 450. I’ve been riding since the mid 80’s and your right I just did not adjust to the bike. Loved the engine though….now maybe the the new Suzuki would…:thinking:

Anyone want a two month old YZ250? :lol:

if you jet it right the bottom end may wake up a little, it could be the jetting that is not letting the motor not getting enought gas from the carb when you first get on it and tha may be able to be fixed with proper jettig and playing with the feul screw

Grey it wasnt Langston that told me that, it was Dubach.
As much as you should know I respect Mr. Dubach, my opinion remains as expressed; it's a good thing, and a pretty impressive reduction in unsprung weight, really, but not a "big" thing. Should it have been done? Yes. Would I do it if I could? Definitely. Would my '06 suddenly handle "much better"? In all likelihood, no. But it would be a refinement.
if you jet it right the bottom end may wake up a little, it could be the jetting that is not letting the motor not getting enought gas from the carb when you first get on it and tha may be able to be fixed with proper jettig and playing with the feul screw
Nope. My '03 would have to predict the throttle being opened to be more responsive. It still bites better than a two stroke, just because it's a thumper.

About Dubach saying that the reduced weight of the caliper being the main reason why the 08 corners better - I am not so sure about that. Langston has been complaining a ton about his bike and now that he has the 08, his results have improved and he seems to have stopped complaining. He even mentioned in a recent video on www.twmx.com that the new bike just corners better. Now my point is this, if all this is because of a lighter caliper, don't you think the factory yamaha team woud have been capable of installing a lighter caliper on his 07 and call it a day? I have to say, i'm with Grayracer on this one. It would take a combination of changes to make a bike noticeablely better, not just one.

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