Basically I'm tryingto figure out a small problem here....I've been in shops for a long time, longer than some of you have even been alive! But I cannot figure this out. It's been a long time, but hardly anu track bike experience for me in those years. I'm trying to help out a friend right now who just picked up a set of Try-all FFW cranks. We've tried two or three different track cogs, and they all seem to have a different thread than on the cranks, a normal freewheel fits fine, but he's trying to use them on a stock bike, with a King rear hub. Are the threads on the cogs different from the standard freewheel threads? Or do you think the Surly cogs are just inferior, and have bad machining tolerances, hence the threads are not deep enough? He's leaving for the worlds in a day, so any help would be greatly appreciated!