Cycling performance depends upon overcoming air and rolling resistance in this research the results of ‘coasting down’ experiments were used by the authors to calculate these components. The experiments were performed in the massive indoor Flower Hall near Amsterdam on a Sunday morning. Anthony Sargeant was the head of the research department which carried out this work.
Gert de Groot, Anthony J Sargeant, Jos Geysel
Medicine and Science in Sports and Exercise
Med Sci Sports Exerc. 1995 Jul;27(7):1090-5
- To calculate the power output during actual cycling, the air friction force Fa and rolling resistance Fr have to be known. Instead of wind tunnel experiments or towing experiments at steady speed, in this study these friction forces were measured by coasting down experiments. Towing experiments at constant acceleration (increasing velocity) were also done for comparison. From the equation of motion, the velocity-time curve v(t) was obtained. Curve-fitting procedures on experimental data of the velocity v yielded values of the rolling resistance force Fr and of the air friction coefficient k = Fa/v2. For the coasting down experiments, the group mean values per body mass m (N = 7) were km = k/m = (2.15 +/- 0.32) x 10(-3)m-1 and ar = Fr/m = (3.76 +/- 0.18) x 10(-2)ms-2, close to other values from the literature. The curves in the phase plane (velocity vs acceleration) and the small residual sum of squares indicated the validity of the theory. The towing experiments were not congruent with the coasting down experiments. Higher values of the air friction were found, probably due to turbulence of the air.