text

1. Bicycle, vehicle usually consisting of two wheels fixed to a frame, steered by handlebars, and
propelled by an arrangement of pedals and gears that are driven by the feet. Different types of
bicycle are tailored for different kinds of riding. Bicycles were immensely popular in Europe and
the United States in the late 19th and early 20th centuries. Their popularity declined with the
rise of the automobile and the motorcycle, and bicycle manufacturers concentrated on producing
bicycles for children. In the late 20th century, however, bicycles enjoyed a strong renaissance in
the United States. The energy crisis of the 1970s, the growing popularity of mountain bikes since
the 1980s, general interest in aerobic exercise and fitness, the growth of bicycle touring and
fundraising events, and the success of American racing cyclists in international racing
competitions all contributed to this renaissance.
All bicycles fall into one of six general categories: touring, mountain, hybrid (sometimes called
cross), utility, racing, or specialty. Components on each type are specially selected to suit the uses
for which the bicycle is designed. The basic equipment on a bicycle includes a lightweight frame of
thin tubing; wheels (usually spoked) with inflatable tires; an adjustable saddle or seat; brakes for
stopping; handlebars for balance and steering; and a drive train, usually consisting of a continuous
chain driven by foot pedals, for propelling the bicycle. The bicycle also may have gears for easy
operation against strong winds and up hills, a suspension system for cushioning against bumps
(particularly over off-road terrain), and various accessories for safety and comfort.