Recurring flats

Question

I've had 4 flats in three rides, all rear wheel. I can't see anything in the tyre, the tyres relatively new, the rims look good. Needless to say I'm getting pretty hacked off with having to keep changing tubes. Two today on a mild 17 mile ride!

Any ideas for anything else I can check for. I've run my fingers through the tyre on every change and can't feel anything. Anything else I can do to ensure there's nothing still in it? Could it be something I'm doing when installing the tube? Anything else you guys can think of?

Answer 1

It could be a problem with the rim tape which runs around the inside of the wheel rim. I'm not sure how you would check this short of replacing it (which is a relatively inexpensive and quick thing to do)

A second possibility is that when you sit on the bike, one of the spoke ends is moving, pushing into the inner tube. Or in a similar vein a small piece of glass may be lodged in the tyre and only stick into the inner tube when your weight pushes on the wheel.

Is your tyre inflated to the correct pressure? If it isn't this can cause "pinch flats".

Things to think about:

• Does the puncture always occur on the inside of the circle made by the tube or the outside?
• Is the puncture always in the same place relative to the wheel rim?
• Is the puncture always in the same place relative to the tyre?

The answers to these may help you narrow down the cause of your punctures.

EDIT: This question may have more information - Frequent blow outs in the same location

Answer 2

Do what Amos suggested to find out if there are any patterns in the flats.

The worst I've had was a tiny piece of radial wire (from blown out car/truck tires) stuck in the thickest part of the tread. It was very difficult to find and only pressed into the tube while riding.

Worst case, if you can't find the source but know the rim & tape are ok, just replace the tire. I carry a spare folding tire on really long rides for that reason.