So I have a Sakae SX road double and I am looking into using these cranks for my fixed gear beater. They are square taper, but I don't know what length BB I should choose. I'll be using a formula rear hub, so ideally I should be shooting for 42mm, correct? Any ideas on which length BB I should choose?
This is the tough part about using a used crank for your fixie build. You either search the hell out of the internet and hope you can trust the answers you get, or start buying bottom brackets and experimenting. Go to a forgiving bike shop and they might let you try a couple. I was going to point you to Sheldon's BB size database, but he doesn't have anything for Sakae.