i am turning my old mtb/trials bike into a single. it currently has a U-brake. but i'm brazing on a I.S. mount for a disc. i need to figure out what rim to buy. it's a 24" rear and has a 26" front. so my choices are limited. i now need to buy the hub so i can respace it and mock up the disc tab. first i have to decide on the rim as that will dictate whether i get a 32 or 36h. any help??? thanks.