Except this classification system already exists, complete with names and regulations specific to each kind. Not hard to understand.
Class A & B <20-32km/h are called Pedelecs or Electric bicycles
Class C <45-50km/h are called Mopeds
Class D >50km/h are called Motorcycles, there's further divisions in this class.
You have to know, not fear, that someday you are going to die. Until you know that and embrace that, you are useless. - Tyler Durden, Fight club. Ditch the fake identity you've created for yourself, walk your own way in a society of mindless drones to become real, you are not your social status.