I need to replace 2 inner tubes on my bike. The tire sidewall indicates (54-559) 26x2 but the rim says 26x1.5/1.75. The inner tube i took out have no dimensions shown on them unlike other ones I've done. What inner tube size should I replace it with 2, 1.75 or 1.5 or other?

Thanks in advance.


1 Answer 1


We get a lot of questions about tube and tyre size names because they're confusing.

In your case the tyre and therefore the wheel are both a ISO or ETRTO size of 559mm across, and the tyre has a width of 54mm, or around 2 inches. Your rim suggests that the tyre should be 1.5 to 1.75 inches in width.

Therefore someone has put a slightly wider tyre on in the past. As long as its not rubbing on the frame or the brakes, you're okay with a 2 inch tyre.

Since you have a 2 inch/54mm tyre, your tubes should be sized for that dimension. So you need a tube that covers the 54mm width of a 559mm tyre (aka a common 26" tyre)

Since you already have a 1.75" tube, it would probably work fine. Butyl rubber stretches nicely, and the only downside is a slightly elevated risk of puncturing, while being a little lighter.

Your third option is to simply patch the existing inner tubes and refit them, presuming they've got holes and no longer hold air. Not a big deal, and cheaper than new tubes every time you get a flat.

  • Much appreciated. I'll consider the tire repair, seems like its a hit or miss based on reviews
    – Wojna
    Commented Jun 5, 2021 at 12:34
  • @Wojna Check out bicycles.stackexchange.com/questions/17334/… the tricks are to buff the area around the hole, to improve adhesion. To let the vulcanising fluid set up for 5 minutes before sticking the patch on, and to search the tyre for the original cause. They can be hard to find.
    – Criggie
    Commented Jun 5, 2021 at 21:49

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