yamaha yz450 06 and up wide ratio trans


55 replies to this topic
  • chris scherbinske

Posted January 29, 2007 - 05:57 PM

#1

For those of you that might be interrested. Yes the 07 wr gears will fit into the yzs. Parts needed are all gears and the main axel. The drive axel can be reused. With this set up total parts will be somewhere around $400.00 depending if you replace seals and other minor parts.

  • grayracer513

Posted January 29, 2007 - 08:13 PM

#2

That's good to know.

  • swatdoc

Posted January 30, 2007 - 12:37 AM

#3

Chris - I am VERY interested in this, as I'm going to be converting an 07 to a street legal Supermoto bike. The wide gear ratios would be very good for the motor on the street. Tall gearing in 5th to keep the revs down, but not too tall in first like you would get with just a sprocket change.
You would't be able to provide a list with part numbers would you?

  • MikeDD

Posted January 30, 2007 - 03:00 PM

#4

Yay! Great info thanks Chris. I have been wanting a lower first and taller 5th to make the bike a little more versitile. I would much rather do this mod than spend $500 for a rekluse. Awesome

  • chris scherbinske

Posted January 30, 2007 - 03:42 PM

#5

WR transmission parts list
axel main 5TJ-17411-20-00
5th pinion gear 5TJ-17151-20-00
3rd pinion gear 5TJ-17131-20-00
4th pinion gear 5TJ-17141-20-00
2nd pinion gear 5TJ-17121-20-00
1st gear wheel 5TJ-17211-20-00
5th gear wheel 5TJ-17251-20-00
3rd gear wheel 5TJ-17231-20-00
4th gear wheel 5TJ-17241-20-00
2nd gear wheel 5TJ-17221-20-00

You'll have to add new head and base gaskets also.

This adds about an additional 16mph over stock gearing and makes 1st alot lower.
have fun

  • swatdoc

Posted January 31, 2007 - 12:51 AM

#6

Thanks Chris - I think this will be a must-do for my project. I notice you do not have a "1st gear pinion gear" listed - is this correct?

  • Budlite

Posted January 31, 2007 - 06:11 AM

#7

With as much money as you are spending and with this much work, I'd get all the parts so that I wouldn't have to diassemble the YZ shafts at all, just replace them. If you decide on a new bikee next year or the year after you could reuse the WR tranny if you swap back before you sell. It's not that much more money. This is the approach I was going to take on my 06 YZ450 but instead I'm just going to sell it and get something later in the year.

  • chris scherbinske

Posted January 31, 2007 - 06:24 AM

#8

1st gear is part of the main axel,(inputshaft) that's the reason 1st gear is not in the parts list. The drive axel assy (output shaft for sprcket) is common to both bikes along with fork drum and shift forks.

  • grayracer513

Posted January 31, 2007 - 08:25 AM

#9

With as much money as you are spending and with this much work, I'd get all the parts so that I wouldn't have to diassemble the YZ shafts at all, just replace them. If you decide on a new bikee next year or the year after you could reuse the WR tranny if you swap back before you sell. It's not that much more money.

It isn't as if changing out the gears on the output shaft is that hard, either. It might look intimidating, but there's nothing to it. What is it, two snap rings? If you can swap them in, you can swap them back out. Adds 3-4 minutes to the operation.

  • swatdoc

Posted February 01, 2007 - 12:20 AM

#10

Does anyone know the gear ratios for the WR tranny? the Yamaha website lists the YZ ratios, but not the WR. I'd like to see a comparison.

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  • grayracer513

Posted February 01, 2007 - 11:54 AM

#11

Does anyone know the gear ratios for the WR tranny?

Primary reduction ratio: 61/23 (2.652)
Gear ratio:
1st 29/12 (2.416)
2nd 26/15 (1.733)
3rd 21/16 (1.312)
4th 21/20 (1.05)
5th 21/25 (0.840)

(I searched the WR forum :ride: )

  • yamasaki

Posted July 22, 2007 - 02:00 PM

#12

i just bought an 06 yz450f yesterday and decided to check the sticky threads and came across this post.

what exactly is it people don't like about the '06 5spd tranny?

thanks guys

  • grayracer513

Posted July 22, 2007 - 04:12 PM

#13

People who ride serious woods trails, or enduro/HS races, or who ride the desert a lot, have a common complaint about all MX transmissions. That is that they have a low gear that's too high for the tight stuff, and a high gear that's not long enough for top end, especially when geared down to cure the first problem. For them, a WR trans is often exactly what they want.

  • swatdoc

Posted July 22, 2007 - 07:51 PM

#14

Also those of us converting our bikes to street supermoto use would like the wider ratios so that when we gear up for a top end that keeps the revs lower at freeway speeds, the low gear isn't too high.

  • yamasaki

Posted July 23, 2007 - 04:39 AM

#15

cool, thanks for the responses guy.

i ride mx only, so, i guess i'm good.

  • projected

Posted November 18, 2008 - 05:03 PM

#16

chris scherbinske - I sent you a PM. Thanks.

  • hillclimbguy

Posted November 18, 2008 - 09:21 PM

#17

This is exactly what I'm looking for. Tired of changing rear sprockets for desert and then the woods.

  • Lowedog

Posted February 22, 2009 - 10:34 AM

#18

Seems like I remember a conversation about just using the WR 4th & 5th or just 5th. Is that possible? I plated my 06 YZ and added lights and would love a taller top gear for dual sporting but I also love the close ratio tranny for the woods I ride.

-Lowedog

  • grayracer513

Posted February 22, 2009 - 07:13 PM

#19

Seems like I remember a conversation about just using the WR 4th & 5th or just 5th. Is that possible?

I believe it is possible. Two things to consider:

  • When mixing gears from one trans to another, at least within the YZ/WR models, the fit of the locking lugs of the native gears to the non-native must be carefully examined.
  • You should look at the ratio set as a whole. There is virtually no way to mix the ratios of the two gearboxes so that it does not create an odd sized gap at the point where the WR ratios begin.


  • erickdj

Posted February 22, 2009 - 07:24 PM

#20

I believe it is possible. Two things to consider:

  • When mixing gears from one trans to another, at least within the YZ/WR models, the fit of the locking lugs of the native gears to the non-native must be carefully examined.
  • You should look at the ratio set as a whole. There is virtually no way to mix the ratios of the two gearboxes so that it does not create an odd sized gap at the point where the WR ratios begin.


I was thinking about the possibility of adding a WR 1st and 5th gears to my 08 yz450, seems like that would be a good choice. Gear gaps wouldn't be too bad, since I don't use 2nd gear too much, or 5th. When I usually use 2nd is because I'm gassing it like crazy in sequence gear by gear from 1st all the way to 3rd or 4th. 5th would be used for open fire roads. Maybe someone that has done the swap could shed some light into the fit between wr/yz locking lugs you mentioned.





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