Hoi you fellas. Answer this noob another question. Most of the roads around here are coarse grained crap and bumpy, and my bike seems byond fault. However on the way into town, we have one bit of super smooth hotmix about half a km long. When I'm pedaling over it I feel a very slight vibration on the power stroke of each leg (I guess I don't spin the best) thought the pedals. It's gone when coasting so it must be due to the drive train. Any idea what it could be and if it is a worry?