Cycling UK have just added various pages on ebikes (or their email has just made me aware of them).
www.cyclinguk.org
I haven't read through any of it yet.
Electric bikes | Cycling UK
Do you need a little extra assistance cycling? An electric bike could be the answer. It's not cheating to ride an e-bike, it offers the chance to start cycling and improve your health or gives current cyclists an added boost to help them cycle further, carry a heavy load or keep a faster pace.
