V_Mark
100 W
I just came across this and am a little confused as to how it works. If it does work, it could be the ultimate in stealth, but I feel that any torque would push against your feet and make it harder to pedal.
https://www.takeonesmallstep.co.uk/Entry/View/2462/Page/8
https://www.takeonesmallstep.co.uk/Entry/View/2462/Page/8