information about tubes? okay, so i ride 20 x 2.4 tires that have a max psi of 110. last night my tire EXPLODED! the shop i buy my stuff from is closed for the rest of tonight and tomorrow and im going to the bmx park tomorrow. i have a old tire that is a 20 x 2.1 that has a tube in it i could use but im worried that it might be to much of a size difference and i don't what it to blow while im riding tomorrow. what do you guys think?
Unless you are particularly heavy, I would not worry about size - not that much difference in load carrying between a 2.1 and 2.4 that it will cause a blowout. Blowouts are caused by a tire failure of some description (bead failure, not seated on rim properly or cut to tire are the most common causes). You say "old tire and tube" - how old and what condition?   

If your choice is ride on the 2.1 or not ride - I know what I would do.