Bicycles Stack Exchange is a question and answer site for people who build and repair bicycles, people who train cycling, or commute on bicycles. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have been riding my bike about 450 miles and following the last ride I noticed the tyre had deformed. I'm riding them at 110 psi, just before the deformation you can see a skid mark. Could it have been down to that?

Wonky tyre

share|improve this question
Is the rim deformed too? What happens when you deflate the tire, does the deformation persists? – Mladen Jablanović Jul 9 '13 at 11:28
Assuming the rim is straight, either the tire is "bruised" (the cord inside is broken) or it has somehow managed to slip sideways on the rim. Completely deflate the tire, try to "re-center" it, then re-inflate, tugging as needed to keep the tire straight as you inflate. If it goes back on straight it was probably just an unlucky bounce off a curb. If it won't straighten up the tire is likely damaged. – Daniel R Hicks Jul 9 '13 at 14:39
There is also the odd chance that this is, eg, a 26 inch tire but there is a 700c tube inside and the tube has gotten folded up on itself. If the above deflate/inflate fails to fix it, deflate again and remove the tube, checking if it's the right size and does not show signs that a part of it has been folded up. – Daniel R Hicks Jul 9 '13 at 14:42
@MladenJablanović no the rim is fine. I deflated the tire and it looks like a recent skid has worn away the top rubber. Looking closely the thread is visible. Just had it replaced by the local shop as it's unusable. – Naeem Sarfraz Jul 9 '13 at 17:11
up vote 8 down vote accepted

The casing is giving way underneath the tread. The casing is made up of woven threads that give the tire its shape and strength. Don't ride it this way as it can get worse or fail catastrophically (blow out).

You need a new tire.

share|improve this answer

Is 110 psi higher than the recommended tire pressure on the side of that tire? Looks like several cords/threads were overstressed and torn in the casing. Is your tire gauge accurate?

What did bike shop employee say?

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.