The calibration of bicycle ergometers

A mechanical dynamometer was constructed to calibrate two electronic and four mechanically braked bicycle ergometers. The work required to operate an electronic ergometer may differ as much as 20% from the factory calibration. The compensation for various cycling speeds may be over 10% in error. The calibration of the mechanically braked ergometer with a weighted pendulum calibrates the braking force on the wheel, but does not take into account the frictional resistance of the chain drive, which is as low as 20 kilopond meters (kpm) at low loads, and as high as 175 kpm at high loads. The mechanical dynamometer for calibration also had a significant error of ± 20 kpm.