goes my bike. It appears to happen when I'm not spinning with even force (i.e. pushing extra hard to get up a hill or something) and when I hit bumps. At first I thought fenders (because the shop replaced this bottom bracket less than 6 months ago but now I'm wondering if it could be the crank or bottom bracket and what I could do to remedy it. I own bike repair manuals and read Sheldon's site but I don't know how to definitively diagnose this and then how to approach the repair/adjustment. This clunking doesn't happen always just here and there but I imagine that it is a big problem...fixies aren't suppose to make much noise, right?