Stupid question: How do you accurately measure your cadence on Zwift or on any other indoor cycling application?
My trainer reports some sort of generic cadence with delays of 3-5 seconds in updating and it is also very dependent (some +/- 20%) on my position on the bike (standing vs on the saddle). A cadence sensor mounted on the crank does not do a much better work: just that its reading does not depend on my position, but the delays are long and its jumps between figures have nothing to do with real life, where it sends a smooth and very consistent reading to a Gamin device.