The weather is getting better, and I have some time to look into this again, plus I scored a spare hybrid battery and want to try using some of the NiMH cells in an eBike project.
Bafang ebike kit-
I notice there's a new revision of the Bafang BPM, but nothing has changed in any of the specs I've read. There are also the QQ motors.
Going to do some reading and thinking.