Last minute bike prep issues for Diamond Dons 1982 CR250 vs. 1983

Racerx930
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Racerx930
Edited Date/Time 8/23/2013 10:42am
OK I've been building an 82 XR500 to ride in the Ultima 4 stroke class. For some reason I thought 1982 and 1983 CR250 forks were the same. I thought the only difference was the 1982 had the built in bar clamps on the triples and the 83 had the bolt on.

Here's where my problems start. I'm using 1982 Triples, and 1983 Showa forks in the triples. Everything here bolts up fine. Now on my front wheel I have to be honest, I'm not sure if it's an 82 or 83. The front wheel and axle seem to not slide far enough over towards the chain side of the bike. The brake plate seems a little too wide not letting the Fork boss slide into the brake plate. My front wheel is wayyyyy off center!
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Racerx930
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Racerx930 4/12/2012 10:48pm
4/12/2012 10:48pm Edited Date/Time 4/12/2012 10:51pm

Racerx930
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Racerx930 4/12/2012 10:52pm
4/12/2012 10:52pm Edited Date/Time 4/12/2012 10:54pm
I might add these are not even the forks I'm using, I needed to move the bike and put these on it. I have another set of 83 forks getting 87 internals in them.

If you notice in the 2nd picture the brake hub is all the way up against the fork. However the knob that slides into the brake plate doesn't reach far enough out. Are the 82 and 83 brake plates different? Can you not interchange wheels etc? I'm at a loss with just a few days left to work on this. This is a totally brand new front wheel and as of right now I can't use it .
tydog
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tydog 4/13/2012 4:53am
4/13/2012 4:53am Edited Date/Time 4/13/2012 4:53am
I cannot help you with your backing plate compatibility problem, sorry but I would like to throw out one word of caution. Please be sure that who ever is doing your 87 cartridge to 83 swap is aware of the machine work that must be done to mate the bottoming cones. I am not trying to be a know it all but I just did this swap and it could not be safely done, IMHO, without it.
Good luck!!!!
bultokid
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bultokid 4/13/2012 6:04am
4/13/2012 6:04am
Save yourself all the hassle on the cartridge swap and just go with RaceTech emulators. I've used the emulators on everything from 35mm Betors to '83 CR480 and work great when set-up. Think they run you about $170 and if you're an AHRMA member you get a nice disount from RaceTech to boot. I think the '87 forks are not legal for Ultima class. I did put '87 front end on my '83 CR480 when ran it in the Pre-Modern class, worked great as well as the front disc is light years better than drum. Look me up at Don's, doing trials on Bul Friday and PV on '82 RM465 #37....cold DosXX await.----Rhett

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vet323
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vet323 4/13/2012 9:03am
4/13/2012 9:03am
Racerx930 wrote:
OK I've been building an 82 XR500 to ride in the Ultima 4 stroke class. For some reason I thought 1982 and 1983 CR250 forks were...
OK I've been building an 82 XR500 to ride in the Ultima 4 stroke class. For some reason I thought 1982 and 1983 CR250 forks were the same. I thought the only difference was the 1982 had the built in bar clamps on the triples and the 83 had the bolt on.

Here's where my problems start. I'm using 1982 Triples, and 1983 Showa forks in the triples. Everything here bolts up fine. Now on my front wheel I have to be honest, I'm not sure if it's an 82 or 83. The front wheel and axle seem to not slide far enough over towards the chain side of the bike. The brake plate seems a little too wide not letting the Fork boss slide into the brake plate. My front wheel is wayyyyy off center!
Is the wheel spinning straight? Hard to tell with the photos, but if the forks are straight and the wheel is straight you may have to machine the end of the brake backing plate where it meets the left side fork (allowing the backing plate to move further left).
Racerx930
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Racerx930 4/18/2012 9:19am
4/18/2012 9:19am
I had so many different issues going on it wasn't even funny. For now I had to end up putting old wheels on it and didn't get all the things finished on it I wanted to. The black wheel was dished out to the left side, however I used almost all the threads on the buchanan spokes trying to pull it back to center and I just didn't have enough spoke. Also the brake plate didn't want to go in the hub with the EBC shoes. I did some modification to them and now they will work. We also fab'd up a 2003 YZ450 Thunder Alley Megaphone pipe to fit it.
Racerx930
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Racerx930 4/18/2012 9:20am
4/18/2012 9:20am
Racerx930
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Racerx930 4/18/2012 9:20am
4/18/2012 9:20am
I also have my trusty 125 ready to go
brothergearhead 8/23/2013 10:42am
8/23/2013 10:42am
Racerx930 wrote:
I had so many different issues going on it wasn't even funny. For now I had to end up putting old wheels on it and didn't...
I had so many different issues going on it wasn't even funny. For now I had to end up putting old wheels on it and didn't get all the things finished on it I wanted to. The black wheel was dished out to the left side, however I used almost all the threads on the buchanan spokes trying to pull it back to center and I just didn't have enough spoke. Also the brake plate didn't want to go in the hub with the EBC shoes. I did some modification to them and now they will work. We also fab'd up a 2003 YZ450 Thunder Alley Megaphone pipe to fit it.
Hey Racerx930,
I'm curious to how your bike handles compared to the twin shock XR500 or tt500?

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