For frames with an oversized (American) BB shell and one-piece crank - which is still pretty common on beach cruisers and lower-grade BMX bikes - you can get a BB reducer kit and use any BB/crankset you want.
http://www.amazon.com/Truvativ-Ameri.../dp/B003KS00EU
Last edited by Scrodzilla; 07-12-11 at 05:23 AM.
Reason: adding link