Tarik Saleh posted a response to Matthews question: <snip> I have found lots of skip tooth "track" cogs to be very oddly threaded, I am guessing they were either for specific hubs, or are actually coaster brake stuff. I put up some photos in the same set of a variety of skip tooth stuff in my bike dungeon, I know the new departure coaster brake cogs are for coasterbrakes, but I am not sure what all of the track cogs are for in the track cog pics, I am guessing some of those are some odd brit thread and others are for coaster brakes and one threads for sure on a normal threaded track hub. So I think the non-offsett stuff might be more likely for coaster brake hubs. <snip>
Tarik Saleh PO Box 208, Los Alamos, NM 87544 tsaleh at rocketmail dot com Bicycles, bicycles, bicycles: http://tariksaleh.com All sorts of bikes blog: http://tsaleh.blogspot.com ++++++++++++++++++++++++ Here's one clue that has helped me: Many inch-pitch cogs have a slot maybe a cm long that runs radially toward the center from between two teeth. That is a clear give-away that the cog was for a coaster brake, not a fixed-gear. Since the coaster can coast (duh), when you break a right side spoke you could rotate to remove the old one and insert the new one through the slot, w/o removing the cog. Now, the nice thing is that these are also (in my experience) a slightly larger thread diameter than the 1.37 English or slightly larger Italian/Campy/Old Paramount hubs can handle, so it is a quick screen for NOT-track cogs.
Your mileage may vary, of course.
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