Can tyres just lose their shape?

jonny_trousers
jonny_trousers Posts: 3,588
edited June 2012 in Road beginners
I know this sounds like a really stupid question, but having fitted a new inner tube after a puncture last night, I've discovered what appears to be a sudden dip in one particular spot on the tyre. My initial reaction was that I'd damaged the rim within the 8 metres or so that I continued riding on a punctured tube, but having inspected things further the rim looks fine. Spoke tension is good too. I obviously then considered that the tyre might not be sitting properly in the rim, but - apart from the fact that I would assume that would create an outward bulge whereas this one dips inwards - again, it looks ok. I even swapped inner tubes, but the problem persists. I'll try fitting another tyre tomorrow, but I would be interested to know if any of you have ever experienced such a thing.

For what it's worth, the tyre is a 23mm Conti Gatorskin and it has flattened off a bit.

Comments

  • topdude
    topdude Posts: 1,557
    Yes, i have one that has developed a kink sideways, looks like the rim is bent but it's just the tyre ?
    It's not a gatorskin by the way.
    He is not the messiah, he is a very naughty boy !!
  • thistle_
    thistle_ Posts: 7,217
    I've had this problem on MTB tyres. Normally it's fixed by putting washing up liquid on the tyre bead/inside of the rim and pumping the tyre up high.

    Make sure you wash it all off though afterwards.
  • desweller
    desweller Posts: 5,175
    If it's a wired bead then there might be a kink in the bead.

    Otherwise it could just be that the tube has a twist in it or the tyre might not be properly seated. A bit of talcum powder can help the bead to slide into place and likewise applying talc to the tube before fitting will help it move into place against the tyre during inflation.

    Some tyre / wheel combinations are a pain in the arse though; I can never fully get the low spots out of the wide tyres on my touring bike :-(.
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  • jonny_trousers
    jonny_trousers Posts: 3,588
    Thanks all!

    So after an awful lot of deflating, massaging of tyre and tube, and reinflating, the issue persisted. So, I took the tyre from the rim again, checked that the beading wasn't damaged (it isn't), rubbed with washing up liquid, refitted and it is now way better. It's still not perfectly spherical, but then again perhaps it never was. It occurred to me that it is the first time I've actually had to fit a tyre to this wheel (a Campagnolo Khasim) and so perhaps itt is a PITA rim from that perspective. I don't seem to have much luck with rims and tyres as my last set - a pair of Easton EA50s were absolute pigs to fit and caused me to shred many an inner tube.

    So is the washing up liquid just acting as a lube?

    Cheers for the advice!