Should I replace my outer (as well as inner)?

OverTheHillAt21 Posts: 102
edited December 2013 in Road beginners
So had my first puncture on my new road bike yesterday and eventually got the outer tyre off (was very tight). I've found a glass sliver buried in the outer and very carefully removed it but it has still left somewhat of a tear in the fabric, maybe 3mm long. I'm not 100% sure whether it is ok to just put a new inner in or not, unfortunately I am over my overdraft limit already so buying a new outer today is pretty out of the question. How can I determine if it is safe? Is it possible to suggest a rule of thumb for how big a hole/tear is ok or is it too subjective? It it was on my MTB I would probably be happy but with the much higher pressures in road tyres not sure on the road bike.

I wouldn't ride it if I'm not confident so if it really needs it I will have to switch to the MTB for a bit until funds improve.

PS the tyre is a CST Czar 700x25C rated 2 stars out of 5 elsewhere on the site... :-(


  • Outer = tyre
    Inner = tube

    3mm may be ok, many people will put a 'boot' in place just in case, an old bit of tyre - or sometimes a bank note, taped to the inside, the idea being just to stop the tube poking out of the hole.
  • keef66
    keef66 Posts: 13,123
    I had a similar dilemma recently. Virtually new tyre which a tiny shard of flint had sliced into causing a puncture. New inner tube fitted at the roadside and inflated just enough to get me home. Once I was home I took the tyre off again and stuck a chunky MTB patch over the tiny slit on the inside of the tyre. Now I can inflate it to it's normal 80 psi without risk of the tube bulging out.
  • Thanks for the replies. Maybe I will give it a go. At least having checked it sounds like the tyre is pretty cheap to replace (and has poor reviews for puncture protection!).
  • Don't know if you saw this link posted this morning in the Bargains thread, might be handy for you. ... 10&afsrc=1
  • Very similar thing happened to me a few weeks back.

    After a bit of research i found the general rule was that if the tyre is split all the way through it will need replacing. If it bulges when at the psi you ride at then it needs replacing. However it sounds like yours might be just a small bit of damage so may be ok. Mine was about a 1cm gash caused by a flint so mine needed replacing which was frustrating as the tyre was not that old
    Cannondale Caad8
    Canyon Aeroad 8.0
  • desweller
    desweller Posts: 5,175
    You can fit a home-made tyre boot to support the inner tube if funds are tight. My preferred solution is to wrap a strip of toothpaste tube around the inner tube in the affected area. A patch of fabric is also a good choice.
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