differences between 06-08

[dempsey55]

are there any significant differences in the 450s between 2006 through 2008??

[grayracer513]

Depends on what the meaning of "significant" is. But if you mean major changes, no. Refinements, for the most part, but real refinements they are, and as such, they're significant.

[Ga426owner]

I would say significant - not a entire refresh.

frame changes - even from 06/07

motor changes from 06/07

clutch changes from 07

exhaust changes

little things - footpegs, clutch perch adj, bar bend 06

[warrior86]

i remember reading they did something to decrease the motor noise and something to the gearbox too i think. I cant get on teh yamaha webpage or i would check.

[grayracer513]

That was on the '08, and it was a reduction in the primary gear backlash.

[adamdf]

I this as potentially the biggest change for 08. Gray can you comment on this?

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.

[grayracer513]

I don't know whether it's the biggest, most important change or not, but the stem length reduction is for weight loss only, which isn't bad, of course, but the weight loss from a 5mm shorter stem and steering head will be limited. And, IMO, no one will be able to feel the difference between a forged or cast bottom clamp. Improved swing arm pivot stiffness will probably be a good thing.

[hey guy]

On www.yamaha-motor.ca it says that the 2008 YZ450F highlights are "New camshafts, intake tract and "shorty" muffler, revised frame and 48mm fork" Why hasn't anyone noticed the new camshafts? Is it a Canadian thing?

[hey guy]

nevermind, they just word it differently on the US site

"Revised intake port shapes, and revised intake and exhaust cam profiles increase combustion efficiency for improved torque and throttle response in the low- to mid-rpm range."

[grayracer513]

the '03-'05 cams were the same. Since then, they've been different each year.

The stock port shape is probably an important point, as Ron Hamp was recently able to put a YZ450 over the 60hp threshold for the first time using the '06 head, something he says wasn't possible with the earlier heads.

[CROGGR]

are there any significant differences in the 450s between 2006 through 2008??

I'll let you know this week as I will be testing one! If the differences are significant I will be bringing one home! Also the 5mm shave of the steering

stem is supposed to do the same thing as raising the forks in the triple clamps 5mm, this is according to the Yamaha rep I spoke to this past week!

[adamdf]

I'll let you know this week as I will be testing one! If the differences are significant I will be bringing one home! Also the 5mm shave of the steering

stem is supposed to do the same thing as raising the forks in the triple clamps 5mm, this is according to the Yamaha rep I spoke to this past week!

Your dealer has them in already!!?? By the way CROGR, how is the kawi treatin ya? I know you own both the YZF and KXF, have you decided which one you prefer yet? I have yet to decide which one i'm going with for 08.

[grayracer513]

Also the 5mm shave of the steering

stem is supposed to do the same thing as raising the forks in the triple clamps 5mm, this is according to the Yamaha rep I spoke to this past week!

Better think about that one a little longer. If you take the 5mm off the bottom, it moves the lower clamp up, but if you run the forks flush, it changes nothing. If you take it off the top, and run the forks flush, you've moved the fork down 5mm, not up.

Even if you move the whole steering head up 5mm without changing the head angle, it doesn't have the same effect as moving the forks up on the current model. It just lowers the CG.

OTOH, sliding the forks up rocks the head forward, and makes the angle steeper, which is why it improves cornering. I'd like to see them go from the current 27 degrees (on the '06) to something closer to 26-26.5. Even steeper would make it turn better, but you can't go too steep on an MX bike without having problems with uneven ground.

[CROGGR]

Better think about that one a little longer. If you take the 5mm off the bottom, it moves the lower clamp up, but if you run the forks flush, it changes nothing. If you take it off the top, and run the forks flush, you've moved the fork down 5mm, not up.

Even if you move the whole steering head up 5mm without changing the head angle, it doesn't have the same effect as moving the forks up on the current model. It just lowers the CG.

OTOH, sliding the forks up rocks the head forward, and makes the angle steeper, which is why it improves cornering. I'd like to see them go from the current 27 degrees (on the '06) to something closer to 26-26.5. Even steeper would make it turn better, but you can't go too steep on an MX bike without having problems with uneven ground.

Hey GRAY....

You are right, imagine that! I was so excited that the rep told me my bike would be in Tues I didn't even think about what he had said......guess what? Bike didn't come in Tuesday so he was wrong on both accounts the jerk!? Thanks for pointing that out! I would have probably lost some sleep over that one a week or two down the line!!!!?