650R USD Fork valving/spring set up

Well after blowing out my fork seals for the second time in a month I tore down the oem forks to find that the chrome is worn off the inner tubes and junked. I have purchased a set of y2k showas from a CR250r and wanting some feedback on anyone that has valved these (or simular) to run on the BRP. Just trying to get a ball park idea to set these up.


215 lbs

Fast intermediate hs woods/ midpack expert desert racer... (Faster in the desert...slower in the woods.)

I want to set these up to be plush when just DS around but able to add some clicks to make them soak up the large g outs when racing or hauling arse in the desert.

Bike: y2k. BRP 650R

Acerbis 6 gallon tank and ds/rallyed out

stock bore, stage 1 cam.

uncorked and race exaust.

rear shock racetech. heavy spring set up for my weight and speed.

I have a set of 03 CRF 450 forks on mine. I didn't change anything in the fork. I was able play with it and get it pretty decent. Then I noticed the back could not keep up at all. I used instructions and a set-up from Bruce's website to change my rear spring and shim stack in the rear. It is realtively good now. I am sure a pro setting it up would be better. Just haven't gotten there yet. Oh, I weight 220 without gear.

Keneroo, Blaker,

What did you guys use to mount your XRR's USD forks. The only aftermarket setup I am aware of is Emig Racing's conversion. But at $525, plus forks, it's scaring me off.

WHat did you do?

I haven't gotten mine installed yet.. just purchased off of ebay.

Here's the link to modifiying the CRF clamp to fit. http://home.comcast.net/~ledrocnoc/CRFClampMods/

when you look at the emig pricing, it's very compairable to the Scotts UTB

mount upper clamp at $750 retail


hell it's all pretty pricey. but.. since I need new fork parts to keep the oems going, I might as well spend the money to do this mod and get what I want.

Any other tips that you guys have would be helpful

[i think .48 springs in those forks may work well for you.

The above link for the triple tree swap is a good'un.

Uh... Thats funny. I did the exact opposite as the link. I left the stock CRF stem in the stock CRF lower clamp. Went to my local machine shop and he machined the top of the steering stem to the same outside diameter of the top of the xr steering stem. Now I could use the stock upper xr bearing. Then for the upper crf clamp, he made thin sleeve to slide between the now narower steering stem and upper clamp. Both very simmilar ways of going about it.

I have had zero problems with this set-up. I did need a CRF front wheel, acutally just hub and axle would work. But the Xr stock caliper bolts right on to the fork.

Now for the cons. For super moto, or even agressive street riding this is the cats pajamas. However, for high speed offroad, I do prefer the stock forks much better. I believe this is due to greater trail on the stock clamps. In tight trails this set-up works fine and the bike jumps amazingly well for what it is.

I think if I can figure out a scotts damper, I could have the best of both worlds. Just not real sure how to mount one. Maybe a CRF upper clamp and XR lower mount, but that would block my dipstick, any suggestions?

I've been doing lots of research on front ends as far as interchangeability goes.

I don't know everything, but what I do have is bearing sizes for the top and bottom of the steering stems. I don't have steering stem lengths.

All years of the XR650R uses 26/47 (ID/OD in mm) bearings for the top and 30/52 for the bottom.

'91 through at least '05 CR250R use 30/52 top and 30/52 bottom.

'87-'01 CR500 use 26/47 top and 30/52 bottom. .41 springs ('95 on)

'04-'06 CRF250R use 30/52 top and 30/52 bottom. .45 springs

'02-'06 CRF450R use 30/52 top and 30/52 bottom. .47 springs

There is a 32906 bearing that is 30/47, which means that using this bearing at the top and a stock bearing at the bottom, a CR250 front end will bolt up. Keep in mind, I DON'T KNOW the steering stem length.

Just as a note, all years XR650L use 26/47 top and 26/47 bottom.

If people want to help me with my research, I'm looking for steering head lengths for the following bikes ('88 to present) - Honda CR125, CR250, CR500, CRF250R/X, CRF450R/X, XR100, XR200, XR250, XR400, XR600, XR650L,R, Kawasaki KX125, KX250, KX500, KLX250/300, KDX200/220, KX250F, Suzuki RM125, RM250, RM250F, RM450F, DR250/350, RMX250.

If I know the steering head length, I'll have a pretty good idea if the stem length is right.

Sorry, I'm not doing Yamaha... I don't have any, and I don't recall that they are particularly noted for their front ends.

PM me with what ever info you have and I'll fill in the charts.... Thanks!

I did look for an adaptor bearing so I would not have to the other crap. I just went to Whistler Bearing in Rapid City, pretty big bearing place and I have purchased many odball motorcycle bearings there in the past. They could not find anything in stock, or in their books to work. We looked at tapered and roller bearings.

On a 2000~2005 CR250R the springs would be a little to soft for a 200~220 pound rider (OK, a lot to soft) they are .43kg/mm same as a stock XR650R but, the springs from a 2002~2006 CRF450R have a spring rate of .47kg/mm and would be a tad stiff but, much better for the heavier rider that gets air and would be great for a 240~270 pound rider. On the valving I would move the cross-over shim up, and add a second one, the rebound shim stack is close on the CRF. Thinner fluid and you would be real happy with what is in the CRF450R for dirt. Anyways the spring rate that you would want for the XR650R would stay the same for your weight but, the shims for the valving would be different.

Thanks BWB63, I will try that this winter prior to studding up. How do I tell which is the cross over shim? And to order a second, do you know the size?

Also, some be wondering why go through this if you can spend less on having the factory forks slicked up... Well, I bent mine in the grill of a car going 55 mph. I got the 450 forks, triple tree, front wheel with black excel and rotor, and axle for $300.

Well it looks as though my 650 might get my cr500 front end and my cr500 might end up with the conventional forks if the stem length is similar.

Good stuff guys you may have saved me a packet of moolah.

Not sure how pertinent my situation is to this thread, but I'll share what I found when I converted mine to USD's. My ATK frame was made to accept the front end from a 1986 XR600. So for this discussion, its pretty much like swapping USD's onto the XR6.

I found a 1991 CR250 with a bad motor for $200, took the complete front end from that, and swapped it on.

What I found is that the distance between the upper and lower triple clamps is identical, the top bearing on both bikes is the same. But the lower bearing on the CR is larger. The top and bottom bearings on the XR6 are identical.

So basically I needed to use the XR stem and bearings, on the CR clamps. To accomplish this, we made a sleeve to install on the XR stem, where it presses into the lower clamp. In effect the sleeve increased the diameter of the XR stem allowing to be pressed into the CR lower clamp.

Then the XR bearings were used. It was a bolt on from there. The steering stops need modifying, as the upper clamp bolt heads hit the tank at full lock.

The stop embosses on the lower clamp will be drilled and tapped, and a bolt installed. Then the bolt will contact the frame stop, allowing full lock adjustment.

My garage has pics of the frame with the forks installed.

There is a 32906 bearing that is 30/47, which means that using this bearing at the top and a stock bearing at the bottom, a CR250 front end will bolt up.

Can anyone tell me where I might be able to find this bearing? Does it really exist? A quick internet search didn't turn up anything. I just bought a complete front end off an '04 CRF450 and I have a set of SCOTTS triple clamps that I'd like to put on my 650R, but if there's an off-the-shelf bearing that will work I'd sure like to know before I do any machine-work on the upper triple clamp.

CrashTestDummyTraveler just sent me a PM with some more information about where he found this bearing. Here's a link to the bearing that he found. By the dimensions, it looks like it might actually work. That would mean that we can BOLT-ON stock CRF triple clamps using the stock CRF steering stem. I'm going to spend some time tomorrow looking into this a little further to see if I can get my hands on one of these bearings to see how well it might (or might not) work.

Thanks CrashTestDummyTraveler!

I just got off the phone with Consolidated Bearing. It's an FAG part number, but they don't manufacture it anymore and no other bearing mfg (I checked with several bearing distributors) makes anything that would cross-reference with that part number. So using the XR650 stem and machining a spacer for the upper CRF triple clamp seems like the best option. I like the idea of using bearings that are readily available anyway.

Here is a cut and paste from another thread I posted in a while back.

If you are putting on a newer CR or CRF front end you don't need to swap the stem. Call a guy named Rob at this place www.evolutionsuspension.com . He has the upper bearing and race to make the CR or CRF trees work. The lower is the same as the 650's so all you need is the upper. I think there is a different washer to go with it too. Ask him about that also. $60 for bearing and race. Pop out your old race, install the new one with the new bearing, then just grind the steering stops on the lower tree to get your desired turning radius.

Thanks. I just talked to Bob at Evolution and he wasn't sure if their upper bearing would work because they've only done swaps on 650L's and 600R's to-date. But we quickly confirmed that the same bearing would work for the 650R, so I ordered one. $65 shipped, although they didn't have it in stock so it will take a few extra days for them to get the bearing, do the machine work and then ship it to me.

Right on. How long ago was that? Just wondering how those bearings held up. I'm a little bit concerned that the cross-section of the upped bearing is so small compared to the stock XR and CRF upper bearings. Any problems?

It's been almost a year since I did the front end. I don't think the bearing will be any problem. I think the upper bearing is a CRF bearing. What he (Rob) does to make it fit is machine down the race. That's why you need to swap races too, not just bearings. The neck wall is so thick on the 650 I'm not worried about the machined down race. It has plenty of back support.

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