Re: Upgrading to 26x2.3 Tires
regular tubes will work. most of them will say on the box "26 x 1.95 - 26x2.125" or something.
i run thornproof tubes in my 26 x 2.3's and the tubes say 2.125, and there's no problem
we used to run 16" tubes in our 20" bmx racers to save weight. not good for flats, though.
most 26" rims will fit a bigger tire. the average cruiser rim is the same rim they use for all sizes, just re-labeled. my rims say for 2.125, but i've seen the exact rim say "for 1.95."
it's just marketing, basically.
i've run tires from 26 x 1.95's to 26 x 2.3's on the same rims with the same tubes.