I had a flat on the way to work today. Not really earth shattering, it was about 5 miles in, only a short walk until the office, where I could fix it in comfort.

But walking the bike, I noticed an odd behaviour. The flat was on the front wheel, and I noticed that once per revolution, the handlebars would turn slightly to the left. Very consistent, just as the valve would get to the bottom of the wheel.

What would cause this? Is it just the valve being slightly thicker than the (now deflated) tube, or did I somehow damage my rim in the short while between the puncture and me stopping the bike?

  • Flat Tires often stick out in awkward ways, especially if you've taken off the tire before and bent the inner wire a bit (inevitable and harmless). It might have just been the side of the tire hitting the brake. It might also be that the inner tube has a slight bump inside around where the valve is and this can cause the tire to "fold" over it and drag the wheel to the left.
    – crasic
    Dec 11, 2010 at 5:06

3 Answers 3


It's possible you damaged your rim, but it should be very easy to check. Turn the bike over and spin the wheel and eyeball it both side to side and up and down. If you have put a flat spot in the rim it should be very noticeable.

It's more likely that it is just the way the (flat) tyre is sitting on the rim, which might well be affected by the valve. If you've got a narrow tyre and a lockring on the valve, that may be holding the tyre on the rim at that point only, causing a wobble when that part of the wheels hits the ground.


A flat tire will rarely damage the rim unless you hit a rather large pothole which resulted in a pinch flat. However, you may need to true the wheel which could be why you're noticing the wheel being out of alignment. Otherwise, it's probably the tire causing the wheel to wobble.

To tell if the rim is off,


This means that you may have put a flat spot in your rim. Another thing, it could have been the hub. The hub has either sealed or unsealed berrings inside, depending on the quality of your bike. To check if the berrings are dammaged, you simply unscrew the axel nuts in order to take off the wheel. You then proceed by taking the lock nut off completely. Then you unscrew the hub bolt only enough to see the berrings. If there is shredded metal inside, you need new berrings or a new hub. Depending on the company of bike, they may warranty it. You'd have to check with them to find out. Do not unscrew the hub bolt all the way. This will break the warranty.

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.