I find the HC TT to be the most painful discipline on the road. Managing your effort and staying positive and focussed is critical. In order to do this -- as mentioned by others -- the really *important* thing is to not go out too hard. If you do, you will blow, and the rest of the race is really going to suck (literally and figuratively). That's why I think a PM or HRM is really great to have on the TT efforts, because it gives you a piece of data that you can put against the adrenaline surge you'll be feeling. If you don't have a PM or HRM, and if it is your first HC TT, I would strongly urge you to try to start out really easy. This is almost impossible to do! I read somewhere that a good TT is paced somewhat like a carpet getting rolled out: a gradual increase in speed.