Originally Posted by Elkhound
OK, you tell me. How can we differentiate a 'motorized bike' from a 'moped' or 'motor scooter' or even a 'motorbike'? Now, it is intuitive that there is a difference, but there has to be some sort of definite, objective criterion--otherwise some leather-clad greaser on his Harley-Davidson can claim that he's just riding a 'motorized bicycle'.
Now, one may argue that the local governments' definitions are 'off', or too restrictive, but that there has to be some 'bright line' should be obvious.
Pedals are one give away, but the usual standard is top sustained speed provided by the motor. The definition varies but the rule of thumb is usually <20 mph. Here in Georgia it is 18 mph or less, in Japan you are not allowed a throttle, pedal activated motor only.