Originally Posted by
Retro Grouch
Nope, it mostly depends on the design of the crank arms. Years ago, crank arms were pretty much straight up and down and BB spindles were in the 120 mm's. More modern square taper crank arms are offset to the point that some require BB spindles less than 110 mm.
Yeah, what he said. OTOH, a relatively recent double crank on a square-taper spindle is probably sitting on a 113mm spindle. On the gripping hand, it can be very brand specific. If you know what brand crank you have, you can look up the length here:
Sheldon Brown's Bottom Bracket Size Database