I just bought a bicycle/bike tube (20"), when i inflate it, 1 side of it goes big/fat and the other just inflates normally, what should i do? , its happened with some of my other tubes.

  • Overinflation - you normally need only 15-20 PSI to check if the tube is leaking. Too much more than that and you risk a blowout. Tubes can carry over 100psi when constrained by a tyre/rim, but on their own they act like balloons and keep stretching.
    – Criggie
    Jan 10, 2016 at 19:00
  • Sounds normal. When you inflate a tube to test it for leaks, parts will expand easily and other parts will hardly expand at all. When the tube is inside the tire this doesn't matter. (To insert the tube in the tire, only inflate it until it's mostly filled out but still limp.) Jan 10, 2016 at 19:46

1 Answer 1


You should mount the tire first and inflate second.

Tubes are not supposed to be inflated outside tires, they will behave like balloons but the material they are made of is not as stretchy.

  • 2
    Why answer a duplicate of your own answer?
    – paparazzo
    Jan 10, 2016 at 19:18
  • Minor correction: You should slightly inflate the tube before inserting in the tire -- just to the point where it's mostly "filled out" but still limp. Jan 10, 2016 at 19:47
  • 1
    The Help Center has a good article on the thinking behind the way in which duplicates should be handled.
    – PeteH
    Jan 10, 2016 at 20:35
  • @Frisbee I noticed the duplicate after replying. I didn't think the reply was bad enough for removing, but apparently someone disagreed.
    – ojs
    Jan 12, 2016 at 19:30
  • @ojs I did not vote you down.
    – paparazzo
    Jan 12, 2016 at 19:32

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