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Keep tearing front tube valve stems.. Why?

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I keep tearing/breaking off my tube (valve) stems in my front tire.. 3 rides on "new to me" bike, and I just ripped/broke off my 2nd stem.

I know that is common in the rear wheel when the tire locks are not tightened, but can it really happen in the front? No tire locks in front.

Ive replaced many tires/tubes and pay close attention to make sure the stem seats perpendicular through the hole, but I don't use baby powder or anything. Can the front tire really be rotating around the rim? Or is there another common issue I don't know about.

Any help/suggestions are appreciated.

98 YZ400.

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No rim lock on the front rim? Look no further, that is your problem.

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Pretty simple to add a rim lock, get the right size, drill a hole in the center of the rim and deburr it install rim lock.

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i like the motion pro lite locks. my drz came without a rimlock so i bought a set of these for the bike. since dunlop 606's are such stiff sidewall DOT tires i need to run them low on pressure, say 8-10 psi, to get any grip up front in the dirt. these locks do an excellent job of stopping the tire from rotating even on the pavement. they let the tire creep just a smidge on the first ride then it's like it's glue to the rim. the valve stem will be cocked just a hair but never moves again. i do powder the tube and only run heavy duty tubes. also don't run the nut down tight against the rim on the valve stem. hondas come with a cool rubber grommet thingie that goes over the valve stem and pretty much seals water out. rocky mtn atv now sells these thing under their tusk label and i use them with good results. lastly, i can't imagine that bike doesn't have a hole in the rim for a lock already. at some point somebody left the lock out cuz it made tire changing easier or some other dumb reason. good luck:thumbsup:

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Wow, I assumed there was no need for a rim lock in the front so I never gave it a second though (had to go look at my other bike to verify it had one on the front).

My guess is the previous owner removed it for balancing (it's street legal) or to make it easy.

Thanks for the info - totally makes sense, and thanks "davegod" for the lite locks tip, I'm gonna grab those.

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thanks "davegod" for the lite locks tip, I'm gonna grab those.

Yeah, I run those front and rear. They feel sturdier than the old metal/rubber style. They are pretty tough too. Racing for miles on a flat usually spells doom for a rimlock, but not these.

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before you do that make sure the nut is all the way up to the valve cap. if its down tight on the rim it will allow no play rip the valve. just give it a go first.

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before you do that make sure the nut is all the way up to the valve cap. if its down tight on the rim it will allow no play rip the valve. just give it a go first.

yeppers

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There’s a bit of truth to barns19 comment. I’ve seen racers run rim locks on the front solely to keep the tire on the rim in case of flat and prevent a DNF.

Without the facts, it sounds like you run low PSI in the front? Less than about 14 PSI? Why? Don’t blame the lack of “traction” per say on the tire, learn to ride. If the bike doesn’t have any traction for the terrain your riding, get another type of tire.

Low PSI does give a larger contact patch, but allows the tire to flex and roll side to side in turns. The valve stem will move up and down in the rim hole. If the stem nut is tight, rip, rip, rip.

If you must run low PSI, then use a rim lock and replace the nut on the valve stem with a rubber gasket. However, it is much safer to use the proper tire for the terrain at the proper PSI, than to jerry rig your bike.

Happy Trails.

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Regarding general tire bead grip to the rim: Windex is great for getting the tire bead over the rim and to seat correctly, since it totally dries away in minutes. Some people like WD40 since it's slippery initially but dries away and leaves the rubber tacky, however WD40 needs a day or two to dry before the rubber tacks off.

i dont believe my yz has one. i just make sure theres high enough psi
Some tires are meant to be used with low pressure. Go above the pressure required for proper "rim clean" and the traction and control drops off rapidly. Over inflating is the last thing I'd do. I hate riding when I cannot trust the front tire and look well up ahead on the track. He needs a rim lock for sure. I guess the knurling marks inside his rims are worn out too.
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