The Motorcycle Quiz

Rotational force created by the crankshaft is transmitted to the motorcycle's rear wheel via the transmission.

Motorcycle engines are generally classified by the number of cylinders they have, the capacity of their combustion chambers or the number of strokes in their power cycles.

During World War I, American and European armies used motorcycles extensively. In 1917, the U.S. military bought nearly one-third of all Harley-Davidson motorcycles produced; in 1918, that figure rose to 50 percent.

A chain, belt or shaft is used to transmit engine power to a motorcycle's rear wheel.

Heavy shaft drives sometimes cause unwanted motion, called shaft jacking, in the motorcycle's rear.

A motorcycle chassis includes the frame, suspension, wheels and brakes.

Cast wheels allow the bikes to use tubeless tires, which, unlike traditional pneumatic tires, don't have an inner tube to hold the compressed air. Instead, the air is held between the rim and the tire, relying on a seal to maintain the internal air pressure.

Riders engage the front brake with a hand lever on the right grip and the rear brake with the right foot pedal.

Since they don't come standard with lights, mirrors, horns or mufflers, off-road bikes aren't street-legal.