Unless there is a freewheel sprocket that would allow both forward and backward spinning?
How would you pedal?
Taking the chain off the rear sprocket
would be the only viable option without custom building some kind of user-switchable internal clutch into your BB or your rear wheel.
That might be a tad inconvenient for a mid drive :wink:
Yes, but it is the only way to do what he wants (be able to lock the pedals and not have them affect the wheel) without redesigning and rebuilding parts of the drivetrain.
For a middrive, it would not be able to be a crank-centric type if the pedals must be able to be locked into position, without redesigning the middrive. It would have to input power into the drivetrain somewhere else, past the pedals. The "simplest" way is a left side drive, totally separate from the pedals; short of that simplest is to have the pedals drive a chain that drives an input sprocket on the motor drivetrain and then the motor drives the wheel via separate chain. A simple freewheel at the pedal chain input to the motor drivetrain would prevent backdriving the cranks and thus allow them to be locked without affecting the motor. If they must be lockable during backwards movement, a clutch must be used instead of a freewheel, that can completely disengage the pedal chain from the rest of the system, or the chain must be removed when the pedals are locked.
Same is true of a left side drive motor system; pedals still need clutch or take off chain.
A hubmotor you just take the chain off (or build a clutch system).
Do the cranks on a Bafang BBS02 freewheel?
Edit: One direction only I am thinking
That was why I asked "How would you pedal?" to his suggestion; if it freewheels both ways then there is no way to drive anything from it (or by it).