Drive-by-wire e-bike?

I am curious what you think about this idea:
An e-bike where pedals drive a motor as a generator that charges the battery and a hub motor that is controlledd by twisting the handle like a motorbike.

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Sounds like you are describing a perpetual motion machine :joy:

This is an interesting concept. What problem do you envision it solving?

Well, it would allow for an e-bike without a chain, which opens up a lot of possibilities in terms of design. Also, you can use this like a motorbike if don’t want to get sweaty (if you take the bike to a meeting, for example) as well as for regular biking.
You could even use it for better workouts, as it is essentially a mix between a peloton (you determine the difficulty through increasing the resistence provided by the generator through a ESC) and a motorbike (you control throttle like on a regular electric motorbike).

In that case my description was wrong.
the energy comes from you pedaling. It is converted to electricity with a small generator, feeding into a battery.
That battery in turn feeds a hub motor in the rear wheel, controlled by a throttle.

That’s what I understood it as. Like a “hybrid bike” where your pedaling does not drive the wheel mechanically.

What problem do you envision it solving?

Ahh I get it.

Bicycles can be up to 98% efficient at translating pedaling into forward motion.

If you introduce a motor as a generator, a charger, a battery, a vesc, and another motor, I’d assume you reduce the efficiency of the system.

Basically you would need to pedal a much heavier bike, quite a lot more, in order to ride the same distance as a normal bike.


the amount of input energy required to charge the battery any useful amount would be to high to see any noticeable improvement over say an twist throttle ebike where you can pedal normally.
i have tested the improvement in efficiency. exact same ride to work in the same time-
only throttle- 46wh/mile
throttle and pedaling-16-30wh/mile
trying to pedal with motor regen on is almost impossible to do, it’s like trying to cycle through custard

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Yes, but maybe also spread out the load. So you could pedal lightly up a steep hill and also pedal lightly down a steep hill. Instead of coasting down the hill and pedaling really hard up the hill.

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This isn’t a new idea. I’ve seen others that didn’t make it past prototype stage. The losses to charge the battery make it too inefficient.


This is already the case with bikes with hub motors. Pedal sensors in the axle just send a signal to the motor. The idea of adjusting the regen is interesting though.

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