tyre keeps popping off..

badly_dubbed Posts: 1,350
edited September 2012 in Workshop
was out on bike yesterday had no probs, going out today later and just got a new track pump....

tyres havent been topped up in a week so they were around 80psi..topped them up to 100-105 and the tyre on the front keeps coming off the rim only at the point where the valve is....back tyres fine.

deflated and re-seated and same happens when re-inflated...

new tyre needed you think? shame as theyre not that old and the rims are brand new.


  • Sounds like it's not seated correctly... I know you've checked. But it is usually the obvious things that we overlook. Might be worth double/triple checking.
    You've no won the Big Cup since 1902!
  • I would check the inner tube first, some cheap inner tubes are a bit over thick around the valve area (ive had new ones supplied with holes in before ive even pumped them up). So check that first and maybe get a decent inner tube first (cheaper option) and see if that helps.

    I would then clean the rim bead of the tyre. I know it sounds obvious, but have you checked the pressure rating on the tyre? it might simply be its not rated for 100-120 psi.

    If it was me i would do
    1. clean tyre
    2. replace inner tube
    3. pump to 100psi

    I would also check the rim of the wheel again, might be some stone or blockage in it.
  • sungod
    sungod Posts: 16,846
    some tubes have quite a wide valve base, it can get in the way of the tyre and prevent the bead seating



    push the valve stem inwards firmly, and hold it there while squishing the tyre to make sure the bead is seated

    ideally, do the above with pump attached so you can inflate partially while holding the stem in, otherwise keep the stem in while you hook up the pump

    once you've got some air in there, let the valve move out and finish inflating
    my bike - faster than god's and twice as shiny
  • well all seems well now cheers, tyres have been up 110ish before, just deflated then put 105psi in and wiggled it about and it held...no bumps lumps so seems fine :) did 45miles on it today so its fixed musnt have been seating properly each time

    thanks guys :mrgreen:
  • Good stuff!
  • Monty Dog
    Monty Dog Posts: 20,614
    I would change the tyres as a tyre popping-off the rim is very dangerous. Sounds like the tyres could be too wide for the rim?
    Make mine an Italian, with Campagnolo on the side..
  • ba68
    ba68 Posts: 156
    What Sungod says, had exactly the same problem the other day as the tube / valve joint seemed too big; pressed the valve stem in while inflating and it's now fine.