How do self-sealing inner tubes work? I understand it protects against objects up to a certain length, but do I need to still remove the offending object eventually? Or do I need to leave it in?

Are they generally reliable and worth it?

1 Answer 1


Self-sealing tubes are filled (well, not completely filled) with a sealant, similar to this used to seal tubeless tyres. When a wheel is spinning, sealant is distributed evenly around the tube, and when the puncture occurs, the sealant should be able to stop the air from leaking. They are quite reliable for small punctures (say, up to 5mmm at a time) but the sealant may lose its properties after a few months so I'd be careful with these.

And whether you need to remove the puncturing object, well it depends. If it's small and could progres into a tube it's better to remove it immediately before the hole increases. And when it's large (say, a larger nail) it could sometimes help stop the leak. However there's no strict rule here, and you have to check what works better in each situation.

  • 2
    On car tires, the sealant forms a layer in the tire. I suspect this is an option for bicycle tubes as well. You can also buy sealants for bicycle tires in the store and add them to regular tubes (e.g. from the Slime brand).
    – Batman
    Commented May 22, 2015 at 17:26

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.