Salzburg, a beautiful day in autumn 2006: the world's best time trialists battle it out for the time trial crown on a difficult 50.8-kilometre course with some tough climbs. At the finish, the winner, Fabian Cancellara from Switzerland, has a lead of 1:29 minutes over the second-placed American, David Zabriskie, and an average speed of 50.6 km/h on the speedometer.
Incredibly fast! What do you have to do to reach such speeds? The answer can be found by looking at it from the perspective of physics: at 50 km/h, it is the air that offers by far the greatest resistance to the rider. Rolling resistance or static friction hardly play a role at this speed. Even in the optimum riding position, the rider needs 82 per cent of his power to penetrate the invisible wall of air. If you are not sitting in the right position on the bike, you will easily need 90 per cent or more. Rolling resistance, the second greatest resistance, follows behind at 15 per cent. No matter how strong your legs may be: without very, very good aerodynamics, it is impossible to reach speeds of around 50 km/h on a sustained basis. You can also put it another way: The "body" is more important than the "engine" in time trialling. However, without a suitable engine, the body won't get really fast either...
Time trials, as the pictures of the racers on their high-tech bikes convey, seem to be a battle of materials. The frames with special geometries consist of elaborately moulded, flat bars. Instead of spoked wheels, there are tri-spokes or disc wheels, and the riders crouch on recumbents. Aero suits made of special textiles and teardrop-shaped helmets are supposed to add extra seconds. Do you really need all that? Which aero trick brings how much? To answer these questions, TOUR, together with former Gerolsteiner pro Uwe Peschel, a proven time trial specialist, carried out comparative tests on the race track in Augsburg.
In the following PDF downloads you will find everything about time trialling:
The following models and brands are presented:
Time trial bikesCervélo P3 Carbon, Cube Aerium Team, Kuota Kalibur, Look 496 Tri, Scott Plasma Ltd.
Liegelenker (Profile, Zipp, Ritchey, Easton, Syntace)
