Track Cogs and Lockrings
I stock track cogs from a variety of manufacturers in 13T-20T. Sometimes I'll have 21 and 22 tooth cogs around, but not always since most people will opt for a smaller chainring before they put a tea-saucer sized cog on their bikes.
If you have questions about cogs please call the shop. Price differences among cogs are generally due to manufacturing tolerances and finish. Most manufacturers charge more for larger cogs, with the break coming at 16-17T. To simplify things I just charge the same price no matter the size. Unless otherwise noted, all cogs are available in 3/32" and 1/8" wideths.
Cogs
Surly and Rockwerks--these look exactly the same and are likely made in the same factory. One says Surly, the other doesn't. $28
Shimano Dura-Ace--very dark brown, almost black color. Produced in 13-16T. If Shimano makes larger track cogs it is new to me. $25
Euro-Asia Imports Deluxe--very nice cog made in the US. Very dark bronze, looks black at a glance .$28
Soma Oxidized Black--black CNC'd cog. $25
Soma Chrome Plated--silver CNC'd cog. $30
Phil Wood--Triple heat treated stainless steel polished to a mirror finish, what'd you expect? Made in the US. $55
White Industries--Splined cogs to fit all current White Industries fixed gear hubs. Made in the US. $40
Lockrings
I can't get very excited about lockrings, if they keep the cog in place they're doing their job. I generally stock a black and silver option for those who just hafta color-coordinate. I also keep some Campy-compatible around or two just in case.
Wheels Manufacturing stainless steel silver lockring. $10
Shimano Dura-Ace so dark brown it's black lockring. $10
Phil Wood Italian Thread Lockring. Fits Phil Wood, Campagnolo and most Italian track hubs. $30