BICYCLE

also called Bike, lightweight, two-wheeled, steerable machine that is propelled by its rider. On a standard bicycle, the wheels are mounted in a line in a metal frame, and the front wheel is held in rotatable forks. The rider, sitting on a saddle and steering by handlebars attached to the forks, turns a driving sprocket attached to two cranks on which are pedals for his feet. Power is transmitted from this sprocket to a second sprocket on the rear wheel by means of an endless chain running over both sprockets. Bicycles are widely used throughout the world. They are easily mastered and can be ridden with little effort at 1015 miles (1624 km) per houri.e., about four to five times a walking pace. The bicycle is said to be the most efficient means yet devised to convert human energy into propulsion. Because it is easy to house and carry, inexpensive to purchase and maintain, and simple in construction, the bicycle is a valuable instrument of self-transport, and provides pleasant recreation and exercise even while being used for purposes of utility. Bicycle touringtraveling or sightseeingis most widely practiced in Great Britain and western Europe, but it also has become popular in other countries, notably the United States; the oldest touring club is the Pickwick Bicycle Club of London, founded in 1870. Bicycles are also widely used for racing, especially in western Europe, Britain, and the United States.