grayracer513, on 25 January 2012 - 10:43 AM, said:
Some points were missed in that.
'05 AOSS forks should be ignored unless you get them extremely cheap. They need a lot of work to rise to the level of stock '06 forks, and frankly, you'd be much better off reworking the WR fork.
I think I mentioned that in my first post.
The AOSS ('05 YZ only) can be made to work reasonably well. The only problem with them is the lack of aftermarket parts available. There is one adventage in using these forks on your YZ. The axle trunions will accomadate the 2mm difference in fork spacing, but this isn't really a bit issue.
grayracer513, on 25 January 2012 - 10:43 AM, said:
YZ125 fork tubes are dimensionally the same except for being much lighter than the 450's, and their use on a WR or even a YZ450 can't be advised sensibly. YZ250F forks are heavier, but use a 10-12mm shorter steering stem, so in order to use those clamps the stem needs to be replaced (pretty sure this is also true of the 125). Either of these or the YZ250 will definitely need springs and revalving to be as correct as stock YZ450 forks would be on the WR.
All '06 YZ's use the same upper tube (
exactly the same part). The 125 does have a different part number for the lower tube (stanchion tube) however the fork tube is the same I.D. and O.D. as the other YZ's. They use the same spring seat, bushings seals, springs, etc. The 125 also has a compression assembly that has lighter valving (probably a good thing for the WR) but the cartridge is identical to the 450. The stock '06 Y125 has a .43 Kg/mm fork spring vs. a .45 Kg/mm spring for your '07 WR (and a .46 Kg/mm for the YZ450). These differences wouldn't make the 125 forks "unacceptable" for the WR and may actually be a better choice considering that one of the common changes to the '06 YZ450 fork was to put in a softer spring to help cornering. The 125 also shares the 10mm shorter steering stem with the YZ250F (the 250 two stroke and 450 are the same length).
grayracer513, on 25 January 2012 - 10:43 AM, said:
The '06-'07 (and later) YZ450 fork is also set 2mm wider in the clamps than the earlier models, and this is corrected by moving the axle lugs inboard 1mm per side. The tubes will fit into the WR clamps correctly, but you find you need to trim the brake side wheel spacer to align the caliper correctly.
Yes, '06+ YZ forks are 2mm wider than '05 and earlier and WR forks but the difference is something that you will never notice. The 2mm difference is made up in the axle trunions, the axles and spacers are the same. The '07 WR front wheel and speedo drive will fit without any problems if you are using '06+ forks in WR triple clamps. The net effect is the front will be offset by 1mm. The 1mm difference in rotor alignment is taken up by the caliper sliding on the mounting pins and causes no problems with the front brake. I have been using '06 YZ forks on my '03 WR450 with '06 WR triple clamps for a year with no problems. I had to change the clamps im my case but you can use your existing triple clamp.
grayracer513, on 25 January 2012 - 10:43 AM, said:
As a finished bike, yes, the YZ450 is stiffer overall, but it is also lighter, and depending on rider weight, that can be enough to alleviate the need for respringing....but not in every case, so be prepared for that. An "off-road"' revalve will probably be desirable.
Yes, the YZ450 would definately need a revalve at the minimum. Replacing the compression spring would also be a good idea.