Inner Tubes

I want to upgrade my tire to a Maxxis Hookworm 24" X 2.5", but i cannot find the inner tube to match its dimensions! I’m concerned that the incorrect size tube will end in an accident or something bad. The closest size i found was the Duro 24"X 2.6" inner tube at Please advise me on this matter. Should i get this tube and end my search or continue searching for a tube that would fit this tire exactly?

Check your local bike store and buy a 24 x 3" IRC Downhill tire.

No need to go to the site for that!

I think you’ll find that’s a very different tyre you’re talking about. One being downhill and knobbly, the other being a smooth slick.

Inner tube sizes don’t have to match exactly. A 24x2.6" inner tube will be fine, but you probably don’t need something that serious unless you’re riding serious off-road downhill or intending to run a very low pressure and ride stairs on it. You probably just want a normal 24" inner tube, like you’d put in the tyre you’ve currently got.


You can use a smaller tube than called for, but, if you use a larger one there will be folds when it’s inflated which will develop leaks. Personal experience with car tires/tubes (tyres/toobs ;)). Consider that some people are using 29" tubes on Cokers. A 2.5 to a 2.6 may be close enough that there won’t be a problem.

Inner tube size doesn’t have to match the tire size exactly. The main thing is to use the same diameter. I’m using a 24x2.5 tube in my 24x3.0 tire right now and I don’t have any problems with it.

There’s one unicyclist who is even using a 29 inch tube in a 36 inch unicycle.

For the hookworm, I don’t think you will need the Duro tube. That tube is a Down hill tube and is extremely thick and heavy. Go to your local bike shop and pickup a standard 24 inch tube. Anything from a 2.2 inch to 2.6 inch should be fine.


Hi guys, couldn’t find an answer to this exactly, sorry if there is and I haven’t found it…

I have a 20x2.5" tyre on my trials uni and here in Aussie I cant find tubes that match this size. I can get 20x2.125" at the local bike shops or a 19" one from Aust UDC

Question is, how much discrepancy is allowed. If like above, someone uses a 26" tube on a 29" uni, can I get away with a 19" trials tire or better to go for the standard 20"?

Any help is much appreciated :slight_smile:

In my experience rubber inner tubes are pretty stretchy. (I’m currently running a 29" tube with my 36" Nightrider tire. No problems so far, and I’m not really expecting any, since I got the idea from other guys here on the forum.)

Check the “ETRTO” size molded in to be sure but it should say something like 67-387 somewhere on the side. A trials tire marked 20x2.5" should be what we usually call a 19" tire, with a 387 bead size. Some companies call it one, others the other. Yeah, it’s confusing but true from all I’ve seen.

But as LanceB says, inner tubes are stretchy and you usually get away with using anything close.

thanks, appreciate it