Weird Auto Deflation?

Haynes
Haynes Posts: 670
edited November 2007 in Workshop
3rd time this has happened. Bike stood around for a few hours after a ride then all of a sudden pshhhhhh and its punctured.

Always on the inside edge, but in different places around the circumferance. I thought it was the rim / rim tape even though it didnt feel sharp so ive added a 2nd tape but its just gone again.

Is it likely to be pinching? Why does it go when its stood up? Any cures/preventions?
<hr><font>The trick is not MINDING that it hurts.</font>

Comments

  • Bronzie
    Bronzie Posts: 4,927
    Could it be a batch of rubbish tubes?

    Had a similar thing happen that turned out to be caused by the edge of the valve hole being a bit sharp - reslved by replacing the rim tape but you've already done that. :?
    It's a Lifestyle! -+-+- Coggan Training Levels
  • off the back
    off the back Posts: 168
    A bit of detective work required ...

    Check the side wall of your tyre for damage after you inflate the tyre. I had a similiar problem last year in tenerife and did my nut in trying to solve it. Wasted 3 tubes before I worked it out. I kept looking at the top only.

    Then check the inside off teh rim, may be damaged and have a jagged edge - if it does may have to file it down.

    Next run your finger along the inside of the tyre in both directions to find any debris.

    Second last are you taking adequate caretting it back on.

    Finally -could be bad batch of tubes as stated above!
  • Haynes
    Haynes Posts: 670
    The weirdest thing is that it goes when i'm not actually riding it or even soon after ive got in, its several hours afterwards. I marked everything with tipex to make sure i found the exact spot and just cant feel anything sharp. I wondered if its something to do temperature affecting the cause enough, what ever that cause is, for it to go.

    Quite a large hole, not just a pinprick. Actually this must be quite a big clue, it doesnt just puncture, it really goes pop - I initially discounted the rubbish tube idea, but the way it just gives out, maybe it is the tube.

    It corresponds quite closely with the indents in the rim tape covering the spoke holes but the rim tape, i mean both rim tapes, dont feel sharp or look damaged.
    <hr><font>The trick is not MINDING that it hurts.</font>
  • Anonymous
    Anonymous Posts: 79,667
    If you are using wheels with the nipples at the hub check that the spoke holes are smooth.
    I had a similar problem which I cured by filing/deburring the edges of the holes. For added security I put squares of insulation tape over the spoke holes before fitting the rim tape.
  • dennisn
    dennisn Posts: 10,601
    Some years back I had a problem with the tire not staying seated on the rim and
    just kind of popping off at times. Replaced the tires and it never happened again.
    It did leave a big hole in the tube, not some small puncture. I say this because I
    believe that "what can happen will". This may or may not be what is happening to your
    tires but I have heard people complain that some cheap tires that they bought had beads
    on them that weren't the greatest and would, at times, under pressure, pop off the rims.

    Dennis Noward

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