The following discipline definitions exist in the AMA:
Requiring little more than a functional motorcycle and an eye for exploration, adventure motorcycling is riding in its purest form. Often associated with big motorcycles sporting knobby tires, adventure riding simply means venturing into the unknown on two wheels.
A registered trail bike is a type of street legal motorcycle that is designed for both on and off-road use. The terms all-road, on/off road, dual purpose and dual sport are also used for this class of motorcycle. Trail bikes are equipped with street legal equipment such as lights, speedometer, mirrors, horn, license plate mounting, and muffler.