4 tubes exploded so far and counting...

cowboyjon
cowboyjon Posts: 89
edited August 2018 in Workshop
I really, really need someone to explain to me what I'm doing wrong with these inner tubes!

I can't inflate tyres to anything over 80 psi without the inner tubes literally exploding and tonight while trying to get my new indoor training tyre up to a decent pressure I managed to do it again!

I use a large cylinder topeak joe blow pump which I have used on my motorcycle and car tyres for years and the gauge is fairly accurate. Even so, after the first 2 tubes exploded I thought the issue may be the reading was false so I bought a topeak digital gauge to check the prest valves and nope - the pump's gauge is almost spot on.

What in the blue hell am I doing wrong here?

Comments

  • cycleclinic
    cycleclinic Posts: 6,865
    tube trapped under the tyre bead?
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • cougie
    cougie Posts: 22,512
    Yep. Must be trapping the tube. Needs to be shoved into the tyre and inflated slightly and checked to make sure it's not trapped.
  • sungod
    sungod Posts: 17,338
    there's nothing wrong with the inner tubes, an inner tube cannot explode inside the tyre

    to burst it needs to expand so much that it fails, that can only happen if it is released from the tyre

    main options...
    trapping the tube between rim and tyre as above
    tyre is not fitted correctly
    tyre is faulty/damaged
    rim is faulty/damaged
    my bike - faster than god's and twice as shiny
  • svetty
    svetty Posts: 1,904
    Rim tape not fully covering the holes?
    FFS! Harden up and grow a pair :D
  • Livewire
    Livewire Posts: 91
    Svetty wrote:
    Rim tape not fully covering the holes?

    That was my first thought, I remember when I got my first set of carbon wheels and used electrical tape to cover the spoke holes. Each time I pumped the tyre up to 100psi the tube would explode, it took me a couple of times to realise what was happening but from then onwards I only ever use specific rim tape on road bike wheels.

    Electrical tape will work on tyres using less pressure, ie; mountain bike tyres.
  • BikerGroveish
    BikerGroveish Posts: 183
    Svetty wrote:
    Rim tape not fully covering the holes?

    This or the rim tape has sunken into the holes enough to have edges that are destroying the tubes. I’ve had poor quality rim tape that has completely come apart at the spoke holes leaving actual holes and not spotted it because the puncture has happened in the dark whilst out on a ride. This has left me limping from puncture to puncture until I got home and noticed what was causing it.
  • cowboyjon
    cowboyjon Posts: 89
    Thanks guys, I think you are onto something here.

    There's a chance the tyre could be pinching the tube but I don't think that's the cause as this has happened across 4 different types of tyre (I've been experimenting) and different sizes and brands of tube. I'll check it though.

    Speaking to a fellow cyclist at work this morning he says it sound's more like there could be an issue with a spoke or a bit of metal swarf or some kind of foreign body inside the wheel. I haven't actually checked this out as I am a beginner/numpty but will as soon as i get home tonight.
  • craigus89
    craigus89 Posts: 887
    I've had multiple punctures because my rim tape slipped and left an almost invisible bit of sharp metal exposed. Run your finger along it even if you can't see anythign wrong. Rim tape is cheap and very easy to fit yourself if you need to.

    I'd be very surprised even for a beginner to get 4 tubes in a row pinched in the tyre.
  • sungod
    sungod Posts: 17,338
    op - did you check to see if they're being holed in the same place? should be readily apparent

    look at the distance from the valve stem, and whether the damage is on the inner or outer edge of the tube

    btw try to be consistent in positioning the tyre when mounting, if you line up the logo with the valve stem it gives you a reference point to detect a tyre problem

    one flat is generally bad luck, more than one (in quick succession) needs investigating
    my bike - faster than god's and twice as shiny
  • craker
    craker Posts: 1,739
    The tubes themselves show where they've failed. If there's a single failure around the inside of the tube, that points to a problem with the rim tape. If there's a pair a holes further up the side of the tube (snakebite) that's what you tend to see when the tube has got pinched between the tyre and the rim.

    Otherwise, on the outer circumference of the tube, there's something sticking through the tyre (glass, flint etc).
  • thistle_
    thistle_ Posts: 7,218
    What does the explosion hole look like in the innertube? Is it star shaped (like an explosion occurred) or is it a like a cut? or a couple of cuts like a snakebite?
  • shirley_basso
    shirley_basso Posts: 6,195
    Run a ball of cotton wall around the inside of the tyre and if there is a sharp, foreign object in there, it will catch on the cotton.
  • natrix
    natrix Posts: 1,111
    Shirley Basso wrote:
    Run a ball of cotton wall around the inside of the tyre and if there is a sharp, foreign object in there, it will catch on the cotton.

    More fun to run your finger round until it hurts and starts to bleed :lol:
    ~~~~~~Sustrans - Join the Movement~~~~~~
  • cycleclinic
    cycleclinic Posts: 6,865
    If the OP is struggling with this as seems likely a visit to an LBS and a course is advisable.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • mfin
    mfin Posts: 6,729
    Shirley Basso wrote:
    Run a ball of cotton wall around the inside of the tyre and if there is a sharp, foreign object in there, it will catch on the cotton.

    Never heard of that, it's quite clever. It will always work on Pinarellos too because most dentists have cotton wool galore.
  • cowboyjon
    cowboyjon Posts: 89
    Upon inspection last night it turned out the last fail (the previous tubes had literally exploded) was in a very particular place - over one of the spoke holes where the rim tape had burst through leaving the hole exposed.

    Wouldn't have thought that would have caused the puncture but it obviously has! I guess the tube expanded inside the spoke hole till it pinched and burst. There is no sharp objects in there though, I'm at a loss as to how the rim tape failed in that exact spot in the first place on a new bike.
  • BikerGroveish
    BikerGroveish Posts: 183
    cowboyjon wrote:
    Upon inspection last night it turned out the last fail (the previous tubes had literally exploded) was in a very particular place - over one of the spoke holes where the rim tape had burst through leaving the hole exposed.

    Wouldn't have thought that would have caused the puncture but it obviously has! I guess the tube expanded inside the spoke hole till it pinched and burst. There is no sharp objects in there though, I'm at a loss as to how the rim tape failed in that exact spot in the first place on a new bike.

    I’ve had exactly that happen. The rim tape used was akin to stiff electrical tape. Very thin very brittle and very nasty. It wouldn’t have taken a lot of jarring from ordinary riding to have caused it in my opinion. I use Velox rim tape now. It’s very good and still quite cheap.
  • imafatman
    imafatman Posts: 351
    Good luck mate. As they say, 5th time lucky. :lol::lol:

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