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Two destroyed tubes in an hour?

Discussion in 'The Shop' started by mr_dove, Sep 1, 2005.

  1. mr_dove

    mr_dove Monkey

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    In an effort to reduce our gasoline consumption my wife decided to ride to a meeting that she had this last weekend. It was about 5 miles away. The bike had been put away for a while due to her pregnancy and childbirth. It sat on the trainer for about 6 months and got occasional use.

    I topped off both front and back tires and checked air pressure at around 50 pounds (for road use).

    She got to her destination without any problems. Turning around to come home after her meeting the tire went flat after about 1 mile. Being the well trained (by me) female that she is, she changed the tube in about 10 minutes and got back underway.

    She made it about 3 1/2 more miles before the second tube expired in the same fashion as the first (more on that in a moment). Being that she was carrying only a single spare tube, she was forced to walk her bike the remaining 1/2 mile home.

    Examining the tubes later, we were unable to find any sign of holes or puncture marks. I guess that's good since She using the Specialized Armadillos, which are nearly impervious to puncture.

    We eventually found that both tubes had gone flat because the stem (Presta) had been forcefully removed from the rubber of the tube. The first one was torn about 1/2 way around the base of the stem while the other one was completely torn free from the rubber.

    I was planning on going down to purchase 2 fresh replacement tubes but I wanted to find out if this is going to be a recurring problem first. Since it already happened twice, it could happen a 3rd, 4th, and 5th times as well.

    What caused this strange tube destruction and how can I prevent it in the future so my dear wife doesn't get stranded? I'm sorry if the post seemed overly long. I wanted to include some information that I thought might allow true technicians to discover the problem.
     
    #1 -   Sep 1, 2005

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  2. Westy

    Westy the teste

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    Be more careful when removing the pump from the stem.
     
    #2 -   Sep 1, 2005
  3. oldfart

    oldfart Turbo Monkey

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    Sometimes when we run too little air the tire slips on the rim and takes the tube with it. This will cock the valve stem over and we correct it later. That can lead to a later failure. More likely though is you got a bad couple of tubes where the valve stem just wasn't vulcanized on as well as it should have been in that factory in the far east.
     
    #3 -   Sep 1, 2005
  4. Biscuit

    Biscuit Turbo Monkey

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    What he said.

    Also check you rim and make sure the valve hole isn't overly sharp. But it's most likely defective tubes, or not enough air (i.e. slipped tire).
     
    #4 -   Sep 2, 2005
  5. Changleen

    Changleen Paranoid Member

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    Damn Asians!
     
    #5 -   Sep 4, 2005
  6. mr_dove

    mr_dove Monkey

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    Is it possible that regular tire changing (running the tire levers along the edge of the tire) could damage it enough so that the tire doesn't sit securely on the rim?

    I guess the current plan is the do a short test ride before relying too much on the new tubes.
     
    #6 -   Sep 4, 2005
  7. Spunger

    Spunger Git yer dumb questions here

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    You know with presta tubes how some come with that little flat nut that goes and holds the presta valve on the rim? I was always told to remove that nut or loosen it atleast so it isn't tight on the rim as if the tube moves around in the rim it will tear that part where the valve meets the tube.

    I dunno but if you're at home I always talc the tubes with baby powder before putting them in as a lube. Schrader tubes just leak air because their valves aren't great to begin with but get the job done. I've never had a presta valve leak or tear like that but I always use the nut on the presta body to hold it in the rim while putting everything together then loosen it 2-3 turns on the presta valve and leave it, that way the tube can move around and not tear.
     
  8. Bicyclist

    Bicyclist Turbo Monkey

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    Are they schrader holes in the rim?