What size tube inside a KH Trials 20"

Well, what size tube should I have inside of a KH Trials 20"

I think it is 20"x2.125"

thats right. when you put the tube in the tire, it may look ridiculously undersized, but once its pumped up itll be fine.

To resurrect an old thread instead of making a new one…

I can vouch that a standard tube looks ridiculously undersized: Here’s a photo of 20x1.75,2.125 tube beside my Maxxis trials tire. However it inflated up to size with no problem!

What are the disadvantages of using a universal tube instead of getting another more beefy tube like the one KH’s ship with?


I’ve wondered about this myself. I’d like to see a larger purpose built inner tube for 19" trials tyres. Like the 24x3" and 26x3" inners, a 20x2.5" inner would be good. I like to run relatively low pressure in my trials uni, which gives it better ‘feel’ IMO, but has the disadvantage of being more susceptible to pinch flats. Bring on the 20x2.5" inners!


i actually talked with GB4 about this very thing today. basically a larger tube helps prevent side wall folding. he suggested 2 things: 1) he’s heard of someone running a moped (scooter) tube in one before. heavy but really sturdy, and 2) finding out what tubes come in those wal-mart chopped bikes with the 20x3 inch tires.

I snagged a small trailer tire replacement tube at an outdoors shop here in germany. Its beefier and wider than your average tube. It is a little heavier but its certainly worth it. The little beast has lasted me over a year while i used to go through regular tubes every one or two months.

Im sorry i cant give you more info on it right now. If i take the tube out someday ill take a pic or read if it has anything written on it. Ill also try to remember which shop i got it from and if i can get more info from 'em.



that`s why I sell this tube in my shop …



that’s a moped tire made by continental.

Has anyone tried this 20 x 3" inner tube? or even this 20 x 4" inner?
These are both Innova inner tubes designed for fat 20" tyres.