Is the cog the free wheel part that the chain connects to on the back tire? I think that is pretty old.

What places do you recommend in brooklyn? I went to a place on the northwest portion of prospect park. They were really helpful and spent a good portion of the day with me, I don't want to paint them in a bad light, but I found myself spending about double what I expected to pay (and I pretty much only put a new creaky chain on the bike and some new tires). I'm thinking about riding around this afternoon and checking some places out. Williamsburg seems to have a few places. There is a place at the end of court street near redhook that I heard was pretty reasonable in their repairs.