Fork Swap from YZ to WR

[Raider925]

For you guys who have done the swap, was it worth it the cost?

Would it be worth to swap to the YZ450F shock as well?

I have a 2007 WR450F and I am currently trying to find a set of 06/07 YZ450F forks and maybe a YZ shock as well.

Edited January 25, 2012 by Raider925

[2grimjim]

All '05+ YZ125-450 forks will bolt right in your bike. There are two differences you need to be aware of; '08 forks have a smaller caliper bracket mount, so you will need an '08+ caliper bracket; The '05 forks are different internally and not quite as good as the '06+ forks.

The '08+ caliper bracket bolt spacing is about 3-1/4 inches apart. Earlier brackets are about 4-1/4 inches.

The WR forks have a small lug cast into the right axle trunion to locate the speedometer/odometer drive. This isn't really necessary and the speedo drive will work just fine in the YZ forks. I have an '03 WR with '06 YZ forks and '06 WR triple clamps and everything works fine.

Unless you do a lot of high speed desert riding, you will probably want to revalve the YZ forks. They are way stiffer than the WR forks. Same goes for the shock.

Edited January 25, 2012 by 2grimjim

[grayracer513]

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.

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.

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.

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.

[Raider925]

Thanks for the replies. Very Informative.

I should have mentioned I am planning to re-spring and re-valve the YZ suspension once/if I get them.

Edited January 25, 2012 by Raider925

[2grimjim]

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.

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).

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.

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.

[miweber929]

So my question everytime I read about someone doing the YZ suspension swap is:

If I have to redo the valving, respring it and dink around with mounts, brakes, etc. anyway, why would I want to do this? Wouldn't I be further ahead to do the same thing to my stock WR stuff? Now I understand that the YZ stuff is "newer" technology and possibly lighter (though I can't see it being that much lighter) but is it REALLY worth the hassle and cost?

Shouldn't a decent suspension shop be able to redo my stock stuff to be as good?

Seems like a lot of hassle for not a lot of return. Except bragging rights, maybe.

Mike

[2grimjim]

So my question everytime I read about someone doing the YZ suspension swap is:

If I have to redo the valving, respring it and dink around with mounts, brakes, etc. anyway, why would I want to do this? Wouldn't I be further ahead to do the same thing to my stock WR stuff? Now I understand that the YZ stuff is "newer" technology and possibly lighter (though I can't see it being that much lighter) but is it REALLY worth the hassle and cost?

Shouldn't a decent suspension shop be able to redo my stock stuff to be as good?

Seems like a lot of hassle for not a lot of return. Except bragging rights, maybe.

Mike

Depends on circumstances and how the bike is being used.

On my '03 WR, I went from the stock 46mm forks to '06 YZ 48mm for no other reason than having a set of YZ forks collecting dust. I happened to have a blown up out YZ450 sitting in my shop. Paid $800 for the YZ and an '02 WR250F. All I had to do was find a set of '06 WR triple clamps.

I think the YZ fork upgrade is probably more appealing to an owner of a bike with 46mm forks. If you are going to go to the trouble of changing the front end, then why not the '06+ YZ forks? The cost difference between used 48mm WR forks and 48mm YZ SSS forks isn't much.

In the case of the OP's '07 WR, It's really dependant on how cheap you can get the YZ forks and if you really need the bragging rights. The YZ fork is better but you can make the WR fork work pretty well.

[miweber929]

Ok, so you answered the question of why the 06+ forks, but again, even if you have the stuff lying around like you did (though you paid $800 for the bikes so it wasn't exactly laying around) what are the benifits other than talk?

So I have an 04, which like you mentioned with your 03, has 46mm forks on it. I've hit a TON of stuff, and my old 00 CR250 had 46's as well and have yet to feel even the slightest bit of flex in either. And normally when the manufacturer makes things bigger OD wise, they make them thinner ID or else they get heavier, so what am I gaining ride, control, weight, etc. wise that makes this make sense?

I guess I just am not seeing this "circumstance" you mentioned where it would make sense. Just asking, this seems to be common thing for some people to do but I've yet to hear really what makes it better considering the work that needs to be done to make them ride correct. been thinking about having my suspension redone at some point; so do I do stock or should I get YZ stuff?

Mike

[Bandit9]

The SSS forks are so much better. Totally worth the swap.

[RichGuy]

I aquired a 07 yz 250f rolling chassis to use the suspension as you are considering. As mentioned, I found later that i needed yz450 triple clamps because of the dimensions. They are ready to bolt on now, but i have since revalved my wr forks with race tech, so i now have a rolling chassi for sale. Everthing is there though to install the forks. i even replaced the seals in the forks and the bearings in the clamps...

[2grimjim]

Ok, so you answered the question of why the 06+ forks, but again, even if you have the stuff lying around like you did (though you paid $800 for the bikes so it wasn't exactly laying around) what are the benifits other than talk?

So I have an 04, which like you mentioned with your 03, has 46mm forks on it. I've hit a TON of stuff, and my old 00 CR250 had 46's as well and have yet to feel even the slightest bit of flex in either. And normally when the manufacturer makes things bigger OD wise, they make them thinner ID or else they get heavier, so what am I gaining ride, control, weight, etc. wise that makes this make sense?

I guess I just am not seeing this "circumstance" you mentioned where it would make sense. Just asking, this seems to be common thing for some people to do but I've yet to hear really what makes it better considering the work that needs to be done to make them ride correct. been thinking about having my suspension redone at some point; so do I do stock or should I get YZ stuff?

Mike

The $800 was spent on two bikes. The 450 has been agold mine for me. I have sold off some of the parts and even used some of the gearbox parts on a 250F I'm building.

Like I said, the update was because I had the old style 46mm forks with rubber bumbpe bottoming controll and had forks that were already paid for to do the upgrade.

Yes the SSS forks work much better.

The Honda you have has the Showa 47mm twin chamber forks. These forks were plagued with problems that still persist on the newest models. The biggest problem with your Honda forks is the spring seat and the small ports on it. The other problem is the very small compression piston. Yamaha made the same mistakes on the '05 AOSS fork but changed the design of both on ths '06 fork. Honda did go to a larger compression piston in '05 but they still use the same choked-up spring seat (Factory Connection makes a Yamaha style spring seat for the Honda's but you have to machine a new groove in the cartridge for the c-clip).

As far as circumstances, I happen to already have the forks. If I didn't, I would have been happy with the '06+ WR forks if the price was right. Like I said, they can be made to work very good too.

The biggest difference I have noticed with the '06 YZ SSS fork on my WR is it they work very well over a wide variety of terrain. These forks were revalved though.

The revalved SSS forks pick up trail junk, rocks and roots very well yet still don't bottom out easily in big g-outs and 60mph hits in the desert. Something I was unable to do with my old 46mm forks even after revalving them a couple of times. It was either one or the other, not both.

I really do like the SSS forks.

Edited January 26, 2012 by 2grimjim

[grayracer513]

So my question everytime I read about someone doing the YZ suspension swap is:

If I have to redo the valving, respring it and dink around with mounts, brakes, etc. anyway, why would I want to do this? Wouldn't I be further ahead to do the same thing to my stock WR stuff? Now I understand that the YZ stuff is "newer" technology and possibly lighter (though I can't see it being that much lighter) but is it REALLY worth the hassle and cost?

Shouldn't a decent suspension shop be able to redo my stock stuff to be as good?

If the '07 WR was mine, I would use the WR fork and revalve/reconfigure the fork using the Phase 4 stuff from SMART Performance. In each case when I've done this for someone they have been very happy with the results. But the internals of the 46mm fork are different from the WR 48's, and the parts to modify the base valve aren't available, so in that case, I'd want to use the SSS stuff

That said, I also like the SSS fork on my '06 the way I currently have it set up, but it's not stock either.

[Raider925]

Man, these forks are harder to come by then I expected. It seems I can find every year except 06/07.

[2grimjim]

Man, these forks are harder to come by then I expected. It seems I can find every year except 06/07.

'08+ forks will work too. You just have to use an '08 caliper bracket. I'm pretty sure a caliper bracket for a Honda will work on the '08+ forks too.

I just picked up a set of '06 YZ450 forks on ebay for $125 last month.

[Raider925]

'08+ forks will work too. You just have to use an '08 caliper bracket. I'm pretty sure a caliper bracket for a Honda will work on the '08+ forks too.

I just picked up a set of '06 YZ450 forks on ebay for $125 last month.

Man you got lucky, I havent been able to find any close to that. More like triple that price.

[gsa102]

Look up the work that Krannie did on his WR450. The stock forks have a mid-stroke harshness and a tendency to deflect, and put me in the hospital. That is after $400 worth of pro tuning.

That is why people change out the stock forks.

https://www.thumpertalk.com/topic/914365-pro-action-suspension/page__fromsearch__1

[Bandit9]

I've seen them in the $350-400 range. Some came with triple clamps too.

I think it is just flat out mean of Yamaha to have deprived WR owners of this fork.

I had mine revalved by my tuner. They are the best forks I've experienced. They soak up everything. Pretty impressive engineering feat if you ask me. They have been out for 6yrs now, and still is the best non-works fork that I know of.

If I get another 450 this year, it will be the new WR, not b/c of EFI, but for the forks.

[gsa102]

I put a set of DRZ conventional forks on my KDX 200 and they are AWESOME for the woods. I was considering doing the same to the WR rather than the YZ swap. The WR wheel fits the DRZ axle, but you need YZ spacers and add a second 3/8" spacer on the brake side. The KDX brake caliper fit the DRZ fork and the WR Disc, and I expect the WR caliper would fit, too.

[MANIAC998]

Conventional forks for off-road are incredible! They are more supple than any Upside down fork I've ever tried. I'm going to have to look into this SSS fork though, to see if they compare. Maniac

[grayracer513]

Your stock '05 and up WR fork can be made to work so well for the kind of riding that the OP describes that you just won't believe they're the same ones you took off. SMART Performance offers a kit, either installed or DIY, that completely reconfigures the base valve, correcting most of the trouble with the fork. The changes are entirely reversible, too, so you can move the kit from one bike to another, or whatever you want, should something like that come up. If you want it installed for you, and Dave's too busy, or you're close to San Diego County, try the other link in my sig. I've done a few of these myself, and had no complaints.

Thing is that even if you pay for the installation, oil and all, it runs about the same as what the SSS forks are selling for, and you would likely need springs and valving for those in any case.