A motorcycle is a two-wheeled vehicle powered by an engine. Motorcycles are one of the cheapest and most widespread forms of motorized transport for many parts of the world.

On a typical motorcycle the driver sits on a seat, with the hands on a set of handlebars and the feet supported by foot pegs.

When the bike is at rest, the rider puts one or both feet on the ground. Engine speed is controlled by twisting the throttle on the right handlebar grip with braking being controlled with a hand lever and foot pedal.

Shifting of gear ratios is controlled by operating a foot lever with the clutch being operated by a hand lever. Steering is accomplished by moving the handlebars.

The inspiration for the earliest dirt bike, and arguably the first motorcycle, was designed and built by the German inventors Gottlieb Daimler and Wilhelm Maybach in Cannstatt (since 1905 a city district of Stuttgart) in 1885.

Almost all commercially available motorcycles are driven by conventional gasoline internal combustion engines, but some small scooter-type models use an electric motor, and a very small number of diesel models exist.

The Displacement is defined as the total volume of air/fuel mixture an engine can draw in during one complete engine cycle. In a piston engine, this is the volume that is swept as the pistons are moved from top dead center to bottom dead center.

The wheel rims are usually steel or aluminum (generally with steel spokes and an aluminum hub) or ‘mag’ type cast or machined aluminum. At one time, motorcycles all used spoke wheels built up from separate components (see wheel building), but, except for dirt bikes, one-piece wheels are more common now. Performance racing motorcycles often use carbon-fiber wheels, but the expense of these wheels is prohibitively high for general usage.