Front valve stems ripping out

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Apr 13, 2000
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#1
I've had this happen three times now to me, and buying a new tube each time (an installing it!) is really starting to tick me off.
My front tube has a tendancy to get the valve stem ripped almost right out once in a while. It just puts a big hole/tear right around the stem and its not possible to fix, or so the tire guy tells me.

I'm pretty sure the reason for this is that there is no rim-lock on the front tire. Running low pressure amplifies this problem I think, as it's much easier for the tire and tube to slide around while braking. So my question is this...

Has anyone ever rigged up a rim-lock on the front tire of their KDX? I'm temped to give it a whirl. I've heard that not attaching the nut to the valve stem can prevent it from ripping out, it will just pull inside the rim (still a PITA, but don't need new tube!).

So, any suggestions or input would be greatly appreciated!

Dave
 

dirt bike dave

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#2
Thought KDX's had front rim locks.

Anyways, if you are tightening up the valve stem nut down to the rim, that is the problem! Back the nut out so that it tightens up against the valve cap. The stem can still move that way, but will not get pulled through the hole. Do the same on the rear even though you have a rim lock.

Back in the old days when some bikes had no rim locks on the rear, we would tap small holes into the side of the rim and put small sheet metal screws into the tire bead, four per side. It worked, but there never seemed to be a need to do it on the fronts. I think you can buy aftermarket rim locks, but you would have to drill a big hole in your rim.

Good luck solving the problem.
 
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#4
Thanks for the replies guys.

DBD, I'll try that tonight when I pop in the new tube. I HAVE been tightening the nut right down to the rim, so I think you're probably right.

88RM250, I was under the impression that my rims were stock. I could be mistaken.

Any other 89-94 KDX owners out there who don't have rim locks?

Dave
 
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#6
Make sure the rim lock you buy is right size for the tire. If there isn’t already a hole position it about 4-5” away from valve which makes getting them on easier.

Easy.
 

Canadian Dave

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#7
Dave your 89 KDX200 didn’t come with a front rim lock nor did my 89. Installing one is a good idea, they’re cheep and very easy to install. Expect to spend 10 to $15., ya about the price of a tube ;)

I completely agree with the other posts, don't tighten down the nut. I spin it up to the cap to prevent it from working its self loose instead. Watch the stem and when you see it laying over deflate the tube and rotate it back in place.

A worn front tire can cause the same problem. The bead is no longer strong enough to grip the rim properly allowing it to spin. .

David
 
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#8
Thanks everyone for the tips. I put in the new tube last night and didn't tighten down the nut on the valve stem. Now when I think about it, why didn't I do that in the FIRST place? That sure explains why I've ripped three stems out in the past year.:cool:

I'll pick up a rim lock after this weekend... C-Dave, you're not in Calgary this weekend are ya? I was thinking about heading up to Waiperous on Monday with a couple of buddies if you're interested...

Thanks again to all for the help!

Dave
 

canyncarvr

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#9
Clean the rim..

when you put your tire on. Use a wire brush.

That step gets overlooked often. There has to be decent 'stick' tween the rim and the bead of the tire, and that isn't going to happen if the rim isn't clean.