Monday, August 16, 2010

Weight vs Power

There has been major corporate competition to lower the weight of racing bikes through the use of advanced materials and components. Additionally, advanced wheels are available with low-friction bearings and other features to lower resistance, however in measured tests these components have almost no effect on cycling performance when riding on flat ground. For instance, lowering a bike's weight by 1 lb (0.45 kg), a major effort considering it may weigh less than 15 lb (6.8 kg) to start with, will have the same effect over a 40 km time trial on flat ground as removing a protrusion into the air the size of a pencil. Also, the UCI sets a limit on the minimum weight of bicycles to be used in sanctioned races[11], to discourage making structures so thin that they become unsafe. For these reasons recent designs have concentrated on lowering wind resistance by using aerodynamically shaped tubing, flat spokes on the wheels, and handlebars that position the rider's torso and arms for minimal drag. These changes can impact performance dramatically, cutting minutes off a time trial. Less weight results in larger time savings on uphill terrain....... more

1 comment:

Siraaj said...

Total weight (rider + equipment) has the most impact on acceleration, so a road time trial wouldn't demonstrate the improvement. A standing-start track time trial or a hill climb would be a better test.