My hybrid bike tire measurement says 700x35c. I ordered a replacement inner tube stating it was 700x35-40c but when it arrived it is actually 700x38-45c. Could I still use this or will it cause a problem, e.g. with my brakes?

  • 4
    Any larger and I would worry, but that much of a mismatch isn't likely to be a problem. I would be suspicious of your supplier, though, if they can't supply the right sized tube. Nov 5, 2015 at 12:05
  • 4
    Possible duplicate of Complete beginner's question: inner tube too big?
    – Móż
    Nov 5, 2015 at 21:09
  • 2
    You're only slightly over the speced size but to be extra cautious you might dust the tube with cornstarch to keep it from sticky-binding to the tire, and after installed pump it up about 3/4 the way up, then deflate it, then pump it up to full desired pressure - you want to work out any kinks and folds from the tube.
    – obelia
    Nov 7, 2015 at 18:02

1 Answer 1


It won't cause a problem with your brakes – the tire casing will prevent the tube from "over expanding."

Your tire is a bit smaller than the small end of the range for the tube. You may find it a little harder to fit in the extra material and it would be good to take a bit of extra care to make sure you don't pinch the tube if you use tire levers.

Be careful to avoid any twists, but it should work. This question, Using a wider inner tube, explains in more detail what can go wrong if the tube is significantly too large, and also points out that inflating the tube slightly will ease installation – especially in a case like this.

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.