A lot of things are being done to keep bikes within the law by some manufacturers and sellers, i have heard of one seller no longer willing to sell derestrictable bikes, and one unwilling to change a sprocket, as this would increase the top speed of the bike by 2 or three mph,i think this is taking things too far,if you bought a 30mph legal 50cc petrol scooter you would be offered derestriction to allow 40mph+ at the first service,i have never heard of anybody being prosecuted for this obvious breach of law,people speeding in cars, are generally allowed around 10 percent over the limit before speed cameras snap you, and the police admit to allowing 80mph plus to go unnoticed on the motorways.Some people appear to be becoming paranoid over the regulations on electric bikes, does anybody really think the police are going to be looking out for people travelling at 20mph on an electric bike,most police officers would not even realise that you were riding an electric bike let alone know the laws on them,and even if you were caught exceeding 15mph , my bike is fully legal 14.9mph assist max but it can reach 25mph plus easily downhill, it would be almost impossible to prove that the motor, and not your own pedal power was responsible for exceeding the 15mph the speed limit.