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Gear ratios of 06 comp to 05 and WR?

The YZ gear ratios are much closer than the WR, and therefore not as useful or functional for trail riding or all purpose use. Note that some folks have installed WR tranny gears in their YZ's.

Ask the question differently....is the 06 YZF 1st gear lower or taller than the 05 YZF 1st gear? Is the 06 YZF 4th gear taller or lower than the 05 4th gear? Does the 06 5th gear equal the 05 4th, or does it give you added top end? Haven't ridden an 06, but I'm thinking of buying.....hoping the extra 5th gear will provide more top end. Thanks, Mark

Thanks for the replies... Does anyone know WHAT the gear ratios are on the 06? As I said, they're not posted on the yamaha-motor website. I'm wondering if I can ride this bike well on the trails or not...

Chas - I thought the swaps were on older bikes? You're saying people have swapped WR gears into the 06+ YZ or 05 and older YZ?

The 4 speed ratios are:

1.929

1.563

1.278

1.050

Primary ratio: 2.818 ('05, 2.652)

The YZ426 5 speed was:

1.846

1.533

1.278

1.091

0.952

Primary ratio: 2.952

The WR450 5 speed is:

2.416

1.733

1.312

1.050

0.840

Primary ratio: 2.818 ('05 2.652)

The '06 YZ450 5 speed is:

1.929

1.533

1.278

1.091

0.952

Primary ratio: 2.652

So, the '06 YZ has the same 1st gear as it did with the 4 speed (slightly lower than the YZ426), and the same 2-5 as the YZ426 did. If you re-gear at the final drive so that low is the same as the old 4 speed (remember, the primary ratios are different), you should have about 10% more top speed.

If you gear a WR450 transmission for a 2nd gear the same as the old 4 speed, you would have gears 2-4 slightly closer spaced than the 4 speed, a low gear about 40% lower, and a top gear 20% higher than the 4 speed's 4th, and 12% higher than the new 5 speed.

I still wonder whether the new 5 speed will interchange with the 4 speed, or in part with the WR450. All four bearings are the same (one has a seal config change), and shift fork 3 and the shift cam are the same as the WR450. It also uses the same clutch boss and basket/drven gear as last year. It would be interesting to find out more.

The WR450 5 speed will drop into any YZ450 '03-'05, but only as a complete unit. See: http://www.thumpertalk.com/forum/showthread.php?t=315799

Grayracer, Thanks, great data. I'm contemplating buying a YZ (06) and was wondering what I'd end up with by installing a 2-3 less teeth rear sprocket. I split riding about 50/50 between MX tracks and desert stuff. I can tolerate only using 2-4 on the MX track by gearing taller to have the topend in 5th. I'm trying to decide between the YZ450F and a KTM 450XC. A dealer here is deep discounting CRF450's but don't think I'm interested. Just sold my 05 YZ250 and want to try the 450 gig. Thanks again, Mark

I added the primary ratios to the earlier post, for those interested.

Thanks a ton Greyracer! Do you think the 1st gear of the YZ is enough to do serious woods/technical riding; or is the WR really necessary?

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I've decided I can't deal with the extra weight of my 05 WR450 any longer; it's wearing me out, and its still too dang top heavy for my shorty legs! So it's down to a YZ450f or a 300exc...

Howver, I searched for the answer to this question; and didn't really find the answer I was looking for... Yamahas site doesn't list the gear ratios of the 06 YZ450f either.

What is the ratios of 1-5 on the 06's, and how do they compare to the 05+ WR and 05 YZXXXf's? Can the slow speed stuff and high speed fireroads still be done without the lower WR first and higher WR overdrive?

Thanks in advance for any help!