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Rigorous and fascinating investigation into the efficiency and potential surprising feature sets of completely chainless/belt-less bicycles. For example:

- Infinite gear range allows optimal pedaling technique, can ensure riders are always in the perfect gear, for higher human efficiency and reduced fatigue.

- Extremely advanced control system inherent to the design also allows real-time tailoring the pedaling resistance for example, detecting which leg is weaker and increasing resistance on that side of the stroke to increase training intensity for the weaker leg.

- Regenerative braking might make this work with a really small battery/capacitor bank instead of a normal sized e-bike battery.

Downsides mentioned:

- Bicycle mechanical efficiency so bad basically necessitates a battery. (But this also allows some really cool future features!)

- Control system software gets incredibly complex and doing it bad results in a terrible rider experience.

- Weight (generator at pedals, motor at wheel, battery)

Other downsides:

- Digital drive operates at 50% efficiency as compared to chain or belt drives.

- Slower on gradients.

50% is actually not that bad tbh, was expecting something like 20%.

I expect this to be a tool for training rather than transportation.

If you were on an e-bike I wonder if that even matters. Just let the drivetrain take more of the strain.
Then might as well have an electric moped or scooter. No strain necessary at all.
Electric mopeds come with a ton of extra requirements (at least in Europe) like insurance, road tax, helmets, licensing and road worthiness certification.
It's pretty bad when you consider a regular chain drive is more like 95%
I am waiting for monowheels you can pedal. IE motorized monowheels with pedals. Watching food delivery men on monowheels I learned that they might be quite functional on Nordic snow and ice. Even more so than bicycles, if the monowheel can sense from minute slippage what the road condition is.
Do you mean something like a self balancing unicycle? It'd have some advantages over a bike, taking up less storage and manoeuvring footprint.
It was a bit hard to watch given that it mentions digital all the time. Why is it called digital? There's nothing digital about electricity flowing through a wire. Digital means that a binary signal is carried rather than say, a signal carried from the audio jack.
It annoyed the heck out of myself also however I decided there is something there that is more than just power transfer.

A chain drive is a connection from the leg action to the wheel turning, the connection here between leg action (and generator) and wheel (and drive motor) is a connection of electricity+signal-data (with a potential battery|capacitor in the mix as well).

The drive motor can contribute data on how hard the wheel(s) is(are) to turn, the generator can contribute data on how hard either leg is downstroking, and there can be controller logic making decisions on how to dynamically route energy to and from the battery, increase|decrease drive motor power, increase|decrease generator drag (on asymetric legs (injury|training).

The "drive chain" here is a hybrid of energy+signal transfer .. but digital drive still seems wrong as that's just the signal portion.

> Why is it called digital?

Marketing.

Nice video Basically, it says that you can take a bike, remove the chain, put a EV motor and a battery and profit

I'd say you can also put a petrol-powerered engine, a big chain, a shift gear, and VROOM ! I've found a name for that new product, we could call it "motorbike" or something