Originally Posted by
ismellfish2
Absolutely no issue with running a freewheel on a fixed threaded hub. My LBS recommends fixed-fixed irregardless because they're more flexible- you can run two cogs, one of each, or two freewheels. It will absolutely not fail if you put the freewheel on right, which is hard to mess up- just thread it on straight.
OK, in all fairness to the naysayers, there are some cases when the hub flange is too close to the end of the treads on a fixed hub, such that a freewheel body will hit the outboard spokes. There was a case reported in a previous thread of this problem with a Dura Ace low flange track hub and a flip/flop fixed/fixed track wheel I recently puchased is like this. Hubs like the Harris/Formula are designed with sufficient clearance that a freewheel will work safely and properly.