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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?

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    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. – Daniel R Hicks Nov 5 '15 at 12:05
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    Possible duplicate of Complete beginner's question: inner tube too big? – Móż Nov 5 '15 at 21:09
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    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 '15 at 18:02
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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.

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