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400SM Forks on DR650

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OK... So I've been doing a ton of research and looking around and I'm still stumped.

I'm doing a USD conversion on my '07 DR650. I scored a set of pristine '05 DRZ400SM forks off ebay for $55.00. Considering the price, and the fact that I can keep a big brake rotor on the bike without brackets, I jumped on it. I also snagged a '02 RM125 triple clamp, wheel, axle, and spacers while I was at it.

I mounted everything up last night and everything fit like a champ except for the wheel spacers. It appears that the distance between the forks at the wheel is 3/16" shorter than it needs to be. I have my XR250, which as a complete 02 RM125 front end on it that I am going to measure when I go home, but as of right now, I can't understand why using triples, axles, and wheels from the same bike will result in an interference. Is there a difference with the lower fork legs on the 400SM forks that is causing the interference? There's no way the forks are cocked, twisted, or in some way misaligned. I've measured everything everyway possible and they all check out square, straight, and true.

Anyone have any experience with this? All I can figure at this point is the lower fork lug (where the Axle goes), must be thicker than the RM forks, so the distance between the fork legs is smaller than the RM.

Any input would be appreciated.

Thanks,

Jay

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All I can figure at this point is the lower fork lug (where the Axle goes), must be thicker than the RM forks, so the distance between the fork legs is smaller than the RM.

Honestly I think you've nailed it. If you can take a measurmeent from the centerline of the fork to the edge of the lug and compare it.

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Yes, but I used a complete 400SM front end - no mixing and matching. I would never assume that the RM clamps, axle, etc. are identical the the SM unless they carry the same OEM part numbers. Same goes for the fork bottoms. It doesn't sound like too big a problem to overcome.

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measure everything, then go too a machineshop and ask them too fix the distances!

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measure everything, then go too a machineshop and ask them too fix the distances!

I did something similar to this on my 99 Vmax except I was swapping in a sport bike wheel in place of the stocker. The hub on the Thundercat 600 was 1/2 inch thicker. I simply took measurements and figured out how much needed to be taken off each side. On one side I was able to have a machinist cut down a spacer but on the other side I had a speedo clutch and the fork. The speedo clutch could not be cut down so I had part of the inner fork leg machined down.

There was not enough meat taken out to compromise the fork leg and everything worked out beautifully.

Front%20Fork%20Leg%20View.JPG

Inner%20View.JPG

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I have 99 showa 49U forks on mine and before had drz400e forks. rm wheels fit both. speedo gear?

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I had to end of doing almost exactly what spradley did. Luckly, I run a machine shop, and have a good riding buddy who's helps me out after work in his garage. We ended up machining new spacers and removing about .230 out of the brake caliper carrier. I got it all finished this evening and took it out for a ride. Seems to ride perfect so far. The wheel is perfectly centered and everything seems to be correct. A couple of good stops to bed the brake pads went exactly as planned and I'll probably start riding it to work Tuesday weather providing. The DRZ400SM forks are almost the exact same length as the DR650 forks, so the ride height is exactly the same. A few speed bumps in the neighborhood felt pretty smooth. I want to get a few hundred miles on everything before I really start working on the forks.

Thanks to everyone for the input.

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I had to end of doing almost exactly what spradley did. Luckly, I run a machine shop, and have a good riding buddy who's helps me out after work in his garage. We ended up machining new spacers and removing about .230 out of the brake caliper carrier. I got it all finished this evening and took it out for a ride. Seems to ride perfect so far. The wheel is perfectly centered and everything seems to be correct. A couple of good stops to bed the brake pads went exactly as planned and I'll probably start riding it to work Tuesday weather providing. The DRZ400SM forks are almost the exact same length as the DR650 forks, so the ride height is exactly the same. A few speed bumps in the neighborhood felt pretty smooth. I want to get a few hundred miles on everything before I really start working on the forks.

Thanks to everyone for the input.

Just curious, where are you guys finding the DRZ 400 forks?

Also Jayazevedo did you use the DRZ's triples as well?

thanks,

Gary

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i think i read somewhere that the triples are different? he said he used rm125 clamps? this must be the problem.

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Yep that was the problem. The DRZSM triples have to be about .200 wider than the RM triples if everything fits right for them based on my experience. I know Jeff used the DRZSM triples, but I know he has an aftermarket tank so he probably got them to clear. My DRZSM forks with the RM triples, when turned lock to lock, just barely make contact with the rubber trim on the stock tank. I couldn't have run the DRZSM triples in my configuration and still been able to use all of the stock steering stops.

I got the forks off eBay. They were listed under some obscure title, and I think I was the only person to look at them the whole 7 days they were listed. I don't even know how I found them. Most of the ones I saw on eBay were in the 400-800 dollar range. I wasn't even ready to buy, but when I saw them for that price, I had to. They were pristine. No road dings or grime buildup or anything. I was totally floored when the arrived at my doorstep.

A 40 mile ride to and from work yesterday flushed out any bugs, mainly just a few little tweaks and a loose bolt or two. The setup, combined with my new DRZ400 Trailtech X2 HID light, are awesome. I'm hoping to see how it goes after putting a few hundred miles on it.

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