Many, many thanks for sharing that; I have been looking forward to a pure electric drive train for ages. By virtue of using a generator, energy store & motor it should be possible to realise any gear ratio, or even concepts such as a "home trainer on wheels" where the input speed and torque are kept constant while you control the vehicle speed like on a moped. As long as the average input power matches the motion power needed that should be fine.

About 25 years ago I was working on a similar concept albeit using a chain, but in conjunction of a torque mixer like the Toyota Synergy drive. The efficiency should be better as most of the power is transmitted mechanically. A pure electric drive has two conversions which will decrease the overall efficiency. Should you be interested: https://medium.com/@peter-wurmsdobler/a-low-maintenance-bicycle-for-shared-mobility-c705bb166b8