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Post by wills on Jan 3, 2011 21:32:50 GMT
i went through 5 inner tubes on sunday , all within a mile on tarmac,the presta valve tore out of the tube on all tubes ,i have a 2.3 tyre,1 of the tubes was a downhill version ,its a new rear wheel ,been mountain biking for 15 years and not had a prob like this before ,do any forum members have a clue , thanks
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Post by gruffalo on Jan 3, 2011 21:37:15 GMT
Check that the edge of the valve hole in the rim hasn't got a sharp edge on it. It's the only thing I can think of that would cause the valves to come away like that.
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Post by wills on Jan 3, 2011 21:45:08 GMT
the rim seems ok ,the hole is bigger than the valve and the valve moves around a bit ,only idea i had was that the tube is moving in the tyre and pulling on valve and tearing the tube around the base of valve ? ive had the wheel about 6 months and been ok till now
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Post by andyl on Jan 4, 2011 10:51:22 GMT
if the rim is drilled for a schrader valve then the presta valve is going to need a shim that fits inside the valve drilling of the rim to accomodate for the change of size (smaller diameter) valve in the bigger hole. mavic rims come like this. some presta tubes also come with a stepped locking washer that you thread on the valve down tight o the rim and the lip on it sits within the hole. its most likely the valve moving in the rim valve hole and then as the wheel turns the valve is being split
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Post by wills on Jan 4, 2011 14:53:27 GMT
thanks andy , it is a mavic and its been drilled for a schrader , been to revolution today and got a shim and nut so hopefully this will be the end of my woes , i used the worlds supply of rubber on sunday !!!!!!
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