I was watching the world championship time trails this week and was not surprised to see the winner of the mens average over 50 kmh and the womens over 40 kmph. My personal best over 24 km was 30 kmh in perfect windless conditions at the end of which my legs were jelly and my lungs just about to burst - can anyone explain the emormous difference in speed - the women cyclists are only small as well and not all have powerful looking legs - is it time to give up cycling and go back to golf ?