Too heavy? You just run the motor in reverse which turns it into a generator and adds friction to do generative braking. There really isn’t any added weight.
Bikes normally have freehubs, a ratchet on the cassette (sprockets) of the rear wheel, when you stop pedalling the bike freewheels, without that the pedals would keep turning.
This makes driving a motor from the wheel impossible without heavily modifying the normal bike mechanics. That’s why regenerative braking on e bikes is rare.
Only very cheap e-bikes have hub motors. They’re not a good idea precisely because they don’t interact with the gearing system. So you lose that functionality.
It’s not worth losing access to gearing just to get regenerative braking because the amount of power being used isn’t worth trying to recoup.
Why would it need a direct drive? A mid drive can do the same thing they just don’t usually since you’d need to gear for it. direct drives are the most efficient at regenerative braking but they aren’t the only type.
Could be done, perhaps, with significant added complexity (and hence maintenance). In practice it is not, to my knowledge there are no mid-mount regenerative system on the market. It is worth noting that mid-mounts are significantly more efficient than hub mount, enough so that even with regeneration mid-mounts have more range for a given battery / wattage. The vast majority of hub mounts also do not implement regeneration.
Too heavy? You just run the motor in reverse which turns it into a generator and adds friction to do generative braking. There really isn’t any added weight.
Bikes normally have freehubs, a ratchet on the cassette (sprockets) of the rear wheel, when you stop pedalling the bike freewheels, without that the pedals would keep turning.
This makes driving a motor from the wheel impossible without heavily modifying the normal bike mechanics. That’s why regenerative braking on e bikes is rare.
Not if you have a hub motor. Those don’t interact with the gear system at all.
Only very cheap e-bikes have hub motors. They’re not a good idea precisely because they don’t interact with the gearing system. So you lose that functionality.
It’s not worth losing access to gearing just to get regenerative braking because the amount of power being used isn’t worth trying to recoup.
Yup, which is also why they’re really hard to pedal if the battery dies.
It needs a direct drive which is more weight than the other systems
Why would it need a direct drive? A mid drive can do the same thing they just don’t usually since you’d need to gear for it. direct drives are the most efficient at regenerative braking but they aren’t the only type.
Freewheel hub would prevent it.
You would need to put the freewheel between the motor and the pedals, and have an always-spinning chain/shaft
Could be done, perhaps, with significant added complexity (and hence maintenance). In practice it is not, to my knowledge there are no mid-mount regenerative system on the market. It is worth noting that mid-mounts are significantly more efficient than hub mount, enough so that even with regeneration mid-mounts have more range for a given battery / wattage. The vast majority of hub mounts also do not implement regeneration.