Converting my EuroCircuits Velomobile to a UK-legal Mid-drive motor

This is my mid-drive conversion for my EuroCircuits Challenger Velomobile. The original motor was a Neodrives system. Unfortunately "NeoDrives" refuse to provide any technical servicing information despite the EU "Right To Repair" laws. For this reason I would suggest avoiding any products from this manufacturer!.

My experience of hub motors in velomobiles is generally positive but they do have a small amount of drag when coasting. This can be avoided by using a standard rear wheel and instead fitting a mid-drive motor.

Perhaps surprisingly, the Bafang BB01/02 motor is completely repairable and every single component can be replaced by a user including internal gears and electronic components. The best feature being the ability to reprogram the controller for different levels of assist. In the UK the laws restrict you to an assist of 250W and maximum assist speed of 25kmh (about 16mph), and mostly disallow the use of a hand throttle so you have to rely on pedal assist sensors. It is possible to argue as to whether my system is truly UK legal, but as far as the actual legislation page on the UK website says.... provided it is genuinely limited to the speed and power (without a hand throttle and no hidden 'turbo' switches) I think they would have to accept it. Most commercial e-bike motors are capable of delivering more than their rated power and are limited by the controller; so if they are allowed it seems unfair to prevent a home-built machine using the same technology.

Anyway... the mid-drive motor seems a definite improvement. Gear changes are better, there is less rolling resistance and the suspension and handling seems better. I have managed to remove two ancilliary batteries to save weight whilst running everything from the main battery. Total weight has been reduced by several kg.