another cog thread.

getting a new chain and new cog. switching my other bike to 1/8th inch. probably sticking with sram pc-7x. has served me well in the past, seemed to hold up nicely.

i've been using a surly 17t cog and it's just fine. i'm looking for a reason to try something new. i'm interested in Milwaukee bicycle co, eai deluxe, all city stainless steel, soma, eighth inch. there are probably more in this price range.

anyone have any good/bad experiences with any of these cogs? just looking for durability, roundness, and something super quiet. any advantage of having a polished cog besides looks? should i be thinking about chainline?