I just bought a 02 XR50 last week with a torn rear valve stem and a 2.75-10 MillVille tire. I did some research on here and bought a new Maxxis HD tube and 1.6 rim lock that my local dealer had in stock. I was going to order a Motion Pro rim lock, but they had another brand at the store and it was only $4 and wasn't one of the plastic ones I read to stay away from. This one is fully coated with rubber though, compared to the Motion Pro or Tusk that has bare aluminum showing. Could the full rubber coating be the problem with the rim lock I installed? That's the only thing I can think of so far. I used baby powder to installed the tube, soapy water mix to install the beads, and let it sit overnight and held 26 psi. Dropped it down to 20 psi and ran it. Held up okay for some woods riding, but then slid the rim when doing some drag racing.

Any suggestions? I'm going to order a Motion Pro rim lock and new tube today.







I did go back and put the broken rubber band back on the rim and covered it with duct tape. Just took these pics of the rim lock first.

I found one post saying the all rubber rim locks are junk. I guess I'll try a different one and find out.

http://www.thumperta...984&postcount=4



If I can't find a Motion Pro today at one of the local shops, I'll try and scrape off some of the rubber coating and give that a try so I can at least ride this holiday weekend. Just an idea.

Edited by SkidooSteve12, 01 July 2011 - 03:17 AM.
New idea added

What kind of motor setup are you running that you are spinning the tire in the rim at 20psi??

I run around 20-25psi on the street, and I've never had a issue, even with my 108cc stroker setup, even when I drop it into gear, and ride as crazy as I can lol

Also keep in mind that doing power slides by constantly locking up the rear wheel has the same effect, in a different way. Instead of spinning the rim inside the tire due to having a performance engine, when you jam on the brakes the rim stops but the tire may slide on the rim a bit. Over a period of time, it moves enough to tear the valve stem.

Well I picked up a Motion Pro 1.6" Rim Lock and swapped out the cheaper one I bought before I knew of a difference. There is a big difference in design, even with the same 1.6" size.

I did shift the tube, but had a pin hole elsewhere on the tube. It is just a stock motor in the 02 XR50 that I just bought. And it all happened while I was carrying my 4 & 5 yr old kids with me (separately), so about 240 lbs total on the bike (with HD springs front and back). I don't think the location of the rim lock should matter? I guess I should have put the time lock across from the valve stem, but have read of different locations that worked.... I have not had a chance to ride the bike again, but think I'll be fine now. And will run 25 psi too.



The Motion Pro VS the EMGO











So I learned my lesson on just waiting and ordering the recommended part instead of using the cheap part that was in stock. I actually called around and found that a smaller local KTM shop stocks the better parts, so I know who to deal with now on certain parts.