I ask this, 'cause I have sprockets from various manufacturers, and have become aware, recently, thatthere is a very slight difference between ISO and english threading, on these sprockets, and that it is NOT advised to go back and forth with different-threaded sprockets on a track hub. I.E., if you put an ISO-threaded sprocket on the hub, then replace it only with an ISO threaded sprocket. And viceversa, for english threaded track sprocket.

I only know for certain that Surly sprockets have ISO threading. But what about EAI? Milwaukee? Shimano? Cobra? Phil Wood? (OK, I don't have any Phil Wood sprockets, but bear with me...) What about those "German" sprockets?

There must be someone who made a little database of sprockets.


P.S. I call them sprockets, because that's what they, technicallly, are. Cogs engage other toothed wheels, while sprockets engage chains.