I'm looking for some help - Hopefully I've come to the right place!! I recently bought a Specialized Langester (08) which I use as my daily commute. I've done less than 200 miles on it, yet the rear cog (the single speed - not the fixed) seems to be making a hell of a racket. I've checked everything visually but I can't see what the problem is - does anyone have any clues... Funny thing is I bougth the single speed as a low maintenace option.. I had less problems with my previous commuter geared bike - hey ho!! Also, if it looks like a cog problem - does anyone know off the top of their heads how to go about replacing the cog? Any help appreciated.