Hey, I bought a second-hand surly cog but I started to worry about using it after reading sheldon brown's warning that some surly cogs could strip a hub. The one I have has the small holes and "surly" etched on the side. Is there any way to tell if its one of the bad ones?


On an unrelated note, while putting in my cartridge bottom bracket today, I cracked the plastic cup just around the splines, not around the threads. Do you think its still usable or do I need to replace it?


Thanks for any info!