Aeroscale is based on short motion tests. The rider just needs to install on his bike prior to the test the Aeroscale device, which consists in a tiny bike computer equipped with a bunch of highly accurate sensors (acceleration, speed, wind, pressure, temperature, humidity, …).
A proprietary protocol and algorithm (patent pending) are then deployed to calculate the two magic parameters : CdA (coefficient of aero drag) and Crr (coefficient of rolling resistance). The duration of the test vary between 1 minute for Aero test only to 3 minutes for Aero & Rolling test.
Trials on fixed drag vehicles have shown that Aeroscale has an extremely low intrinsic variability, around 0.001m² (or 1W aero power at 43 km/h), representing only 0.4% of a time trialist CdA of 0.25m². This is to date (to the knowledge of Aeroscale team) the lowest variability by far recorded for an outdoor test device.
Thanks to this outstanding repeatability, Aeroscale is able to discriminate very tiny aero differences, in the range of a tennis ball, as illustrated below :