24" is aimed more at street riding. Spins, etc. But can still be used for everything else (excpet comps) Ashton ET24s were popular. Really nice to ride, but cracked and snapped easily. Not sold anymore either. As '6ft-midget' said, Leeson make and sell custom frames. Just give them a ring, i'm sure Clive could sort you out. 24" trials specific parts can be hard to get hold of, as that area of the sport is much smaller than the rest. 24" Maxxis High Rollers etc are available, and 26" front disc forks can be used. (Although my mate did have some steel Pashley forks with the mounts moved down) Apart from that, bars and stems, cranks, everything else is the same as you would get on a 26" trials bike.