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  1. #1
    Genius
    Reputation: 6bobby9's Avatar
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    Oct 2008
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    853

    No good Schraeder valve repeatedly tearing from tube

    I posted this in the Tooltime area of the main forum but maybe u guys can help.

    Alright. I got some Kenda Excavators 4 weeks ago and I've been through eight inner tubes . Up until then I have have had zero flats for the last 1.5 years. Now with these new tires every single tube is tearing at the point where the valve connects to the tube. I came to realize that the tube is sticking to the tire which is what is causing the rupture as the tire is torqued from hard breaking or climbing. I googled and found one or two other people with this problem and it was recommended to put some talcum powder between the tube and tire so that the tire would "slip" along the tube therefore alleviating the pressure on the valve/rim. I have done this but it hasnt really worked. I have tried this with both schrader and presta's and am spending more time driving to buy new tubes then riding....

    I never had this problem with my other tires..... I love these new Excavators but I have know idea how to fix this. My tire PSI is between 33-35 and they are just stock Mavic rims that came with the Cannondale Prohet 5 when I bought it 2 years ago.

    I welcome any ideas.
    Last edited by 6bobby9; 07-13-2009 at 11:58 AM.

  2. #2
    banned
    Reputation: Mtn. Biker123's Avatar
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    Sep 2005
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    7,330
    Check to make sure there are no burrs (sharp edges) on the inside of the bore for the valve stem. Are you using Stans in the tubes as a sealant?

  3. #3
    High Alpine Adventure
    Reputation: DaGoat's Avatar
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    Sep 2008
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    If I were you I'd go...

    Tubeless Baby... Tubeless!!!
    Dug-Da-Goat

    Something changes at 12,000'
    ...so welcome to the Odyssey!

    Building your trails at FooMTB

  4. #4
    mtbr member
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    Jan 2004
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    Tubeless, Stan's or otherwise might be a solution, but...

    ...if you could prevent the tire from slipping on the rim then the problem "should" be solved. Maybe apply "fan belt dressing" from the auto parts store to the tire bead. The stuff is kinda sticky.

    Seems like you have too much power and too much traction!

    Anyway, best wishes with the problem.

    Terry

  5. #5
    mtbr member
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    I'd think the talcum powder should've worked if your diagnosis is correct. Is it both front and rear failing with equal regularity? I'd put your old tires back on just to make sure that there isn't an unknown variable lurking, like something going on at the valve hole as B suggested.

    One other possiblity is that the tires have an unusual manner of lateral flex that's tweaking the tubes, as opposed to the rotational forces that you suspect.

    Yet another possibility is that it doesn't have anything to do with your riding. Are you getting all these flats while you're riding, or did you piss someone off, or do you have mice, or a Jack Russel Terrier ... ?

  6. #6
    Fragilie
    Reputation: Eric B's Avatar
    Join Date
    May 2004
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    763
    Buy a new tire.
    It's Better To Die On Your Feet Than To Live On Your Knees. (Emiliano Zapata)

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