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  1. #1
    Genius
    Reputation: De La Pena's Avatar
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    No good Schrader 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.

  2. #2
    LA CHÈVRE
    Reputation: Dan Gerous's Avatar
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    Try more powder maybe?

    If talc powder doesn't help... check the valve hole in the rim, if the edge is really sharp from the drilling, it can cut the rubber of the tube around the valve stem. Had this happen on a bike, I sanded/filed the edge smoother and never had the problem again.

    Also, what are you using to pump the tire? Some hand pumps wiggle a lot when pumping and can sometimes do similar damage. A floor pump with a hose is better, and my favorite portable pump is the Topeak Morph series, they have a hose and a little folding foot so they behave more like a floor pump.

    Another thing but only applicable with Presta valves, the little lockring that tightens on the valve stem, against the rim, don't put it too tight, it can pull the valve and damage it's base. A lot of people don't even use those...

    DAN.GEROUS.NET : MOUNTAIN BIKING : CYCLOCROSS : ROAD :

  3. #3
    mtbr member
    Reputation: gemini6's Avatar
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    My floor pump causes this issue if your not careful. I just spray a bit of water on the valve stem before I put the pump on. Oh and I hold the valve stem when I take the pump off.
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  4. #4
    banned
    Reputation: Jerk_Chicken's Avatar
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    Try less powder. Think about it.

  5. #5
    LA CHÈVRE
    Reputation: Dan Gerous's Avatar
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    KY maybe then?

    Haaa the joys of tubeless...

    DAN.GEROUS.NET : MOUNTAIN BIKING : CYCLOCROSS : ROAD :

  6. #6
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    Reputation: Jerk_Chicken's Avatar
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    I welcome any ideas.
    How about not posting in every random forum and putting this thread in the wheels and tires forum so people who have experience can try and help?

  7. #7
    Genius
    Reputation: De La Pena's Avatar
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    Quote Originally Posted by Jerk_Chicken
    How about not posting in every random forum and putting this thread in the wheels and tires forum so people who have experience can try and help?
    I only posted in 3 off the 100 or so forums in this place buddy. Those being Tooltips (obviously), Cannondale (my bike manufacturer) & The New Mexico Forum (where I live). I did not see the wheels and tire forum. Hopefully not all of your 16,000 posts have been so critical to a newbie to mtbr.
    Last edited by De La Pena; 07-13-2009 at 03:13 PM.

  8. #8
    mtbr member
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    Ignore him, he will go away, did the same to me few weeks back...

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