A motorized bicycle is a bicycle with an attached motor used to power the vehicle, or to assist with pedaling. Sometimes classified as a motor vehicle, or a class of hybrid vehicle, motorized bicycles may be powered by different types of engines.
Motorized Bicycle
Here's a guy doing about 30mph on his bicycle that he's put a motor on. We would have hung around longer, but the beach patrol was closing the gates and we had to get our car off the beach
Ed's motorized bicycle
Front-wheel drive monstrosity or incredible conveyance? YOU DECIDE