Or you can come to the darkside of the force and experience Haibike Yamaha, tried, tested, reliable, powerful and you can have two front rings that change like a normal bike.
Bafang is just a motor you need the whole bike read this short thread and then tell me you are not interested.
http://www.pedelecs.co.uk/forum/threads/oxygen-mtb-off-road-speed.26609/
Other categories of exemption include:
HM Coastguard and Port Authorities
Certain operational vehicles used by the London boroughs
The armed forces
Royal Parks Agency
Breakdown organisations
It does not state current or retired armed forces ??