What's a good (cheap) roadbike price likely to be second hand?  My Specialized Hardrock HR is nice, but as an ATB, it's both heavy and I can only get a max of 39mph out of it (I don't think I can break the 40mph barrier on the hill I tried it on!)?

How do roadbikes fare with potholes etc?  Exeter's roads aren't exactly smooth these days...

Out of curiosity, has anyone tried riding one of those Olympics bikes in a velodrome?  Is the cambre of the track as steep as it looks?  I bet I'd fall off!