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XR400 USD fork conversion help

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i have the new CR500 forks and clamps on my bike now but i dotn know what to do about the steering stop issue. anything helps. thanx for your time

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I finally have all my parts to start in on my conversion. I have a front end off a 2000 CR125. I just started some of my machining on the stock CR triple clamps. I havent got to the steering stop portion yet, but for right now I am thinking about making some small ones to the size I need once i get everything mounted up and using a small bolt to bolt it onto the clamp, or see if it can be welded on without weakening the lower clamp. I have a couple of pictures so far that I am still uploading to my site, but will post them once they are finished.

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Ok here are a couple of pics I have so far of my clamps I modified.

I had to mill down the stock CR steering stops, cause it looked like to me it would hit the oil cooler.

Starting to mill the lower clamp

After I got everything milled down and somewhat cleaned up.

After finished with lower clamp

The last pic I have so far is the top clamp. I was thinking I was going to have to mae a new steering stem. I did some measuring and noticed that the bottom clamp is dang near the exact thickness as the stock XR 400 lower clamp. The top clamps are different, so I figured I could mill the under side of the top clamp so it would be the same thickness as the top XR clamp and therefore still be able to use the stock steering stem. If it doesnt work, I am not out much.

Finished upper clamp

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I drilled and tapped two 5/16 holes in the lower clamp where the grade 8 bolts (that I used) would contact the frame in the exact same location that the stock XR steering stops made contact with the frame. I put a locknut on the bolts and now have adjustable steering stops. My forks are now at Factory Connection for a massage in the valving department.

Thumper, I found a much better solution to the steering stem dilemma. I had the stock (I used CRF front end) steering stem turned down to meet the required 26mm in the bearing seat areas, and had the two threaded areas re-threaded to meet the XR requirements. This way you dont have to press a bushing in the lower to accomidate the smaller XR stem (seems like a hack to me). When finished you have about 1/4 inch extra stem at the top (which I had removed). You will still need a 0.40 bushing to reduce the top clamp hole to the right size for accomidating the XR stem dimension. :banghead:

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Thumper, I found a much better solution to the steering stem dilemma. I had the stock (I used CRF front end) steering stem turned down to meet the required 26mm in the bearing seat areas, and had the two threaded areas re-threaded to meet the XR requirements. This way you dont have to press a bushing in the lower to accomidate the smaller XR stem (seems like a hack to me). When finished you have about 1/4 inch extra stem at the top (which I had removed). You will still need a 0.40 bushing to reduce the top clamp hole to the right size for accomidating the XR stem dimension. :banghead:

I had thought about that, but I didn't have the stock CR steering stem to work with, just the clamps. Either way it should still work. Thanks for the idea of the steering stop. If you have some pictures that would also be helpful.

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Thanks for the idea of the steering stop. If you have some pictures that would also be helpful.

I dont have any place to host them. I could take some and possibly e-mail them.

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Here is another idea I incorporated into my customization. While I had the front end apart I drilled and tapped a hole in the steering neck on the frame to accomidate an angled grease zerk to grease the steering stem bearings with high temp waterproof grease. This eliminates the need to take this apart to re-grease it and by keeping grease on these parts they should last alot longer.

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Rockjockey, you can host pics with no hassle and no charge at Tinypic.

Pictures can be uploaded directly from your computer. Look forward to seeing more examples since I'm in the process of a USD conversion for my XR250.

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So There Is No Bearing That Will Allow You To Have The Size Of The Steering Neck And The Stem Without Machining It??????????

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No,not the CR/CRF stem. I got a physics lesson at the bearing supply house on this,the inner diameter of the XR bearing is 26mm and the outer is 47mm.The inner of the CRF bearing is 30mm and apparently you cannot make a tapered roller bearing that will take those kind of forces inside of the alloted 15mm. He said the rollers would be too tiny after figureing in the thickness of the inner and outer races. Go figure I tried the easy method first,but no luck. I was lucky enough to have a friend who is a machinist.

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