Motorcycle

Factors of a motorcycle's ergonomic geometry that determine the seating posture include the height, angle and location of footpegs, seat and handlebars. Factors in a rider's physical geometry that contribute to seating posture include torso, arm, thigh and leg length, and overall rider height.
Legal definitions and restrictions
A motorcycle is broadly defined by law in most countries for the purposes of registration, taxation and rider licensing as a powered two-wheel motor vehicle. Most countries distinguish between mopeds of 49 cc and the more powerful, larger, vehicles (scooters do not count as a separate category). Many jurisdictions include some forms of three-wheelers as motorcycles.