'06 YZ450F 5spd gearing

Ok, here are the tranny ratios for the new 5spd for those who are curious.

Primary reduction ratio- 61/23 (2.652)

1st- 27/14 (1.929)

2nd- 23/15 (1.533)

3rd- 23/18 (1.278)

4th- 24/22 (1.091)

5th- 20/22 (0.952)

sprockets: countershaft 13, 49 rear.

After riding it all weekend i never touched 5th gear, didn't need it, fourth pulls HARD seemingly forever...can't wait to get this thing in the desert.. :applause:

Thanks, Endo.

I've been looking for this.

Gear Final Drive Difference

2006 YZ 450 Gear ratios Ratios Ratio Between

Primary reduction ratio- 61/23 2.652

1st- 27/14 1.929 8.35

2nd- 23/15 1.533 7.95 0.40

3rd- 23/18 1.278 7.70 0.26

4th- 24/22 1.091 7.51 0.19

5th- 20/22 0.952 7.37 0.14

sprockets: countershaft 13/49 rear. 3.769

2005 YZ 450

Primary reduction ratio- 61/23 2.652

First 27/14 1.929 8.22

Second 25/16 1.563 7.86 0.37

Third 23/18 1.278 7.57 0.28

4th. 21/20 1.05 7.35 0.23

sprockets: countershaft 14/51 rear. 3.643

The gear ratios are considerably closer than the 2005 model, I like it.

Thanks for the info!

Looks like the primary and final gearing changes are almost a wash.

So 1st-3rd is almost the same as the 4 speed, the only diff. being the primary and final ratios (actually 2nd is taller on the '06 by a few %), the net effect is the new bike is geared slightly lower 1st-3rd, due mostly to the lower net gearing of the combined primary/final ratios, but w/ a smaller 2nd-3rd gap (and larger 1st-2nd).

4th gear is the old 426 ratio (24/22), but w/ the diff. primary/final combo is about 6% slower than the 450 (note: primary ratio changed in '05, I'm using '04 spec), which was taller than the 426.

So in 4th, about 5 mph slower, but about 8 mph faster overall, than the 4 spd.


Pending any math errors......

Looks right. The trans is gear for gear the same as the YZ426 ratios were except for the 1.94 1st gear (the 426 had a 1.85). It's pretty much what I had been hoping to see, really. This way the gearing gaps are about the same, subject to the overall gearing, as the 4 speed, with an extra gear tossed on top of the pile. I see a top of 95 (on paper) at the rev limit with stock gearing. :applause:

Nice info on gearing. Looks like I am fine with my 03'yz450 since my riding areas never allow me to open er' up past 3rd gear pinned.:applause:

I was curious as to what everyone's manual says for basic weight of the 04',05'&06' yz450 models? My 03' has 249lbs basic weight(bike with all fluids in it). thanks

The trans is gear for gear the same as the YZ426 ratios were except for the 1.94 1st gear (the 426 had a 1.85).

Dang, I didn't even notice that.

The primary/final net change from the 426 to the new 5 speed is less than 3%.

Sort of makes the 4 speed look like a stop-gap solution. :applause:

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