A motorcycle or motorbike is a single-track, two-wheeled motor vehicle powered by an engine. Styles of motorcycles vary depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions. In many parts of the world, motorcycles are among the least expensive and most widespread forms of motorised transport.********************These motorcycles mimic the style of American machines from the 1930s to the early 1960s, such as those made by Harley-Davidson, Indian, Excelsior and Henderson, even though they have benefited from advances in metallurgy and design. The riding position places the feet forward and the hands up, with the spine erect or leaning back slightly, which many find to be more comfortable for long-distance riding. The riding position of American style Cruisers and Choppers evolved from the saddle and riding position used by Western Cowboys.This position allows greater long distance comfort, with some compromise of control. Chopper-style motorcycles would be categorised as a type of cruiser.