My reasoning that it's probably doable was based on efficiency.
What is the end-to-end efficiency of the generator, electronics, and motor combination? If it's 75% efficient, then you need to pedal 33% harder than normal[1]. If it's 66% efficient, then you pedal 50% harder.
Unfortunately, I can't find real data, so those efficiency numbers are guesstimates. Electric motors and generators can be very efficient, and I would hope that they'd use efficient ones for an application like an ebike.
As a point of reference, pumped hydro can be 70-80% efficient[2], and that involves a motor, a generator, and mechanical losses. That's not an apples to apples comparison, though.
---
[1] Where normal means a 100%-efficient link between pedals and wheel. Actual bike chains aren't, but they appear to be 95% or more.
What is the end-to-end efficiency of the generator, electronics, and motor combination? If it's 75% efficient, then you need to pedal 33% harder than normal[1]. If it's 66% efficient, then you pedal 50% harder.
Unfortunately, I can't find real data, so those efficiency numbers are guesstimates. Electric motors and generators can be very efficient, and I would hope that they'd use efficient ones for an application like an ebike.
As a point of reference, pumped hydro can be 70-80% efficient[2], and that involves a motor, a generator, and mechanical losses. That's not an apples to apples comparison, though.
---
[1] Where normal means a 100%-efficient link between pedals and wheel. Actual bike chains aren't, but they appear to be 95% or more.
[2] https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit...