which gear box do most like? yz or wr?


10 replies to this topic
  • stroker yz426

Posted February 05, 2008 - 11:57 AM

#1

so i have almost finished my third stroker yz 426 (well not anymore but..) and i was thinkin about swaping some gears from the wr into the yz and then i thought well if im going to take some i guess ill replace all the gears from the wr, :worthy: granted i know that third and fourth are the same on both machines, but i havent ridin a wr with this engine so i dont know how low first is and how high fifth is
does anyone out there feel that the wr is tooo steep of a first gear? and well fifth is fine i only use fifth on sunday's or at the dunes so it doesnt matter too much if it drops a bit more into "overdrive" so to speak. all your input will be great valued :busted:

  • grayracer513

Posted February 05, 2008 - 12:16 PM

#2

...i know that third and fourth are the same on both machines,

That's not correct.

  • stroker yz426

Posted February 05, 2008 - 12:36 PM

#3

really since when did they change, because last time i looked in my manuals they were the same, the wr use a different 1 2 5 gears

  • grayracer513

Posted February 05, 2008 - 02:37 PM

#4

2001 WR426:
  • 5BF-17131-20-00 GEAR, 3RD PINION (16T)
  • 5BF-17141-20-00 GEAR, 4TH PINION(20T)
  • 5BF-17231-00-00 GEAR, 3RD WHEEL (21T)
  • 5BF-17241-00-00 GEAR, 4TH WHEEL (21T)
  • Ratio in 3rd = 1.313:1
  • Ratio in 4th = 1.050:1
Source: Yamaha Parts manual

2001 YZ426F:
  • 5BE-17131-20-00 GEAR, 3RD PINION (18T)
  • 5BE-17141-30-00 GEAR, 4TH PINION (22T)
  • 5BE-17231-00-00 GEAR, 3RD WHEEL (23T)
  • 5JG-17241-00-00 GEAR, 4TH WHEEL (24T)
  • Ratio in 3rd = 1.278:1
  • Ratio in 4th = 1.091:1
Source: Yamaha Parts manual and 2001 YZ426F(n) Owner's Service Manual

  • yz4fun

Posted February 05, 2008 - 08:05 PM

#5

Greyracer513 :busted: :worthy:

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • rtgincnm

Posted February 05, 2008 - 08:44 PM

#6

I've been thinking of changing my '07 YZ450 to a WR gearbox.

Here are some calculations from a spreadsheet I got off of TT. I picked the sprockets to try to match first gear.

Works out to a top speed of 96mph for the YZ and 124 for the WR. That is at 11000 rpm.:busted:

EDIT: the columns don't line up but the last number in the row is the overal ratio in that gear.

YZ07
Primary Ratio 61 23 2.6522
Secondary Ratio 49 13 3.7692 Overall
1st Gear 27 14 1.9286 19.2793
2nd Gear 23 15 1.5333 15.3282
3rd Gear 23 18 1.2778 12.7735
4th Gear 24 22 1.0909 10.9054
5th Gear 20 21 0.9524 9.5206



WR07
Primary Ratio 61 23 2.6522
Secondary Ratio 45 15 3.0000 Overall
1st Gear 29 12 2.4167 19.2283
2nd Gear 26 15 1.7333 13.7913
3rd Gear 21 16 1.3125 10.4429
4th Gear 21 20 1.0500 8.3543
5th Gear 21 25 0.8400 6.6835

  • grayracer513

Posted February 05, 2008 - 09:10 PM

#7

Refigure your top speeds for 10K or 10.5. The bike will never pull 11 grand in 5th with that kind of gearing. Then reduce it by 5% for tire slip on pavement, or 10% (at least) on dirt.

As far as matching low gears, one of the advantages of the WR box is in having a low gear low enough to pick through a rocky wash yet still have a little leg at speed.

  • stroker yz426

Posted February 07, 2008 - 11:17 AM

#8

ok so should i pull the whole tranny from the wr or should i take the three gears i want? what would you do?

  • grayracer513

Posted February 07, 2008 - 04:53 PM

#9

The gear spacing would be more consistent if you used the whole WR trans. Otherwise, the jump from 2-3 will be a little larger than in the WR, 3-4 will be closer than any other in the trans, and the 4-5 gap will be larger than the WR, also.

  • rtgincnm

Posted February 07, 2008 - 06:01 PM

#10

Refigure your top speeds for 10K or 10.5. The bike will never pull 11 grand in 5th with that kind of gearing. Then reduce it by 5% for tire slip on pavement, or 10% (at least) on dirt.

As far as matching low gears, one of the advantages of the WR box is in having a low gear low enough to pick through a rocky wash yet still have a little leg at speed.


I agree these calcs have no corrections for real world just a way to compare setups and differnt bike gear ratios.

Are you saying that it is possible to mix and match WR and YZ gearing without too much trouble?

  • grayracer513

Posted February 07, 2008 - 07:56 PM

#11

It depends. Within the 426 family, you can mix/match, and some have done it, but if you plot out the ratios, the spacing gets to be odd when you start doing that. I don't see a combination that I really like in it.

The trans parts can be mixed to some extent (exactly how much remains to be seen) on '06 and later YZ450's and the '07 and later WR, but the same caveats about ratio spacing apply.

The early 450's, '03-'05 YZ's and '03-'06 WR's are an all or nothing swap, since one is a four speed and the other a five. Nothing from one trans fits the other.





Related Content

Wiki
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info


Articles
  • 0 replies
Forums
Photo
Motocross

Thinking about Yamaha 250... by Arctic Pride


Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies
Forums
Photo

James Stewart back on a YZ450F by YamaLink


Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies
Forums
Photo

100 hrs on 2014 yz450f, shim valves or replace them? by ttr230rider6


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  79 replies
Reviews

Yamaha YZ450F 2017 by Chris.GVS


Yamaha YZ450F 2017
  • - - - - -
  • 0 reviews
 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.