my road bike got a puncture in the front wheel yesterday while I was riding down a big slope, it happened when I was braking the bike then I heard a pop. I stopped and replaced with a new tube, resumed riding, and another pop when I was down a small slope, I remember I braked a bit as well. Two punctures appeared to be near the valve. two punctures near valve

I found a hole in the tire, could it be the cause of two consecutive punctures? enter image description here

Also found that side of the wire has a lot wear enter image description here

while the other side of the wire has no wear at all enter image description here

I checked the rim and its tape, didn't find any obvious spike or anything.

Question 1: do I need to replace the tire?

Question 2: what causes the wear on one side of the tire?

update: just found out the second tube I replaced, is a 650/18-25c tube, my rim is 700...

  • 1
    Looks to me like your brake pad may be rubbing the tire on one side and needs adjusting. Also always make sure you check your tire as well when changing a flat. A good method is to run your hand around the inside diameter of the whole tire. That way a sneaky thorn doesn't stay behind and pop your newly replaced tube.
    – Nate W
    Commented Mar 14, 2016 at 16:53

2 Answers 2


It seems that brake pad is touching your tire on the one side. Make it parallel to rim and/or move it a little bit down, if you don't same thing will happen to your new tire! Park tool manual example (via http://www.parktool.com/blog/repair-help/linear-pull-brake-service)

  • thanks mocniak, as checked, the left front brake pad was bit high
    – Chris Chen
    Commented Mar 21, 2016 at 22:06

I would replace the tyre even if it's not the cause of the puncture as the bead is coming away. I'd do it reasonably quickly but I would take the risk of riding home or to the bike shop on it.

Do you know if this bit of the tyre was anywhere near the punctures? I put the manufacturer's logo next to the valve when I fit a tyre to make working this out easier.

By the way, tubes can take a lot of stretch. I've seen a 24" tube survive on a 26" wheel.

  • You should probably also check over the rim in case one side is rough/damaged/rusty. Do you always park the bike in the same orientation relative to the prevailing weather?
    – Chris H
    Commented Mar 14, 2016 at 8:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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