ETYM Pref. bi- + cycle.
Has two wheels; moved by foot pedals; SYN. bike, wheel.
Pedal-driven two-wheeled vehicle used in cycling. It consists of a metal frame mounted on two large wire-spoked wheels, with handlebars in front and a seat between the front and back wheels. The bicycle is an energy-efficient, nonpolluting form of transport, and it is estimated that 800 million bicycles are in use throughout the world—outnumbering automobiles three to one. China, India, Denmark, and the Netherlands are countries with a high use of bicycles. More than 10% of road spending in the Netherlands is on cycleways and bicycle parking.
The first bicycle was seen in Paris 1791 and was a form of hobby-horse. The first treadle-propelled cycle was designed by Scottish blacksmith Kirkpatrick Macmillan 1839. By the end of the 19th century wire wheels, metal frames (replacing wood), and pneumatic tires (invented by Scottish veterinary surgeon John B Dunlop 1888) had been added. Among the bicycles of that time was the front-wheel-driven penny farthing with a large front wheel.
Recent technological developments have been related to reducing wind resistance caused by the frontal area and the turbulent drag of the bicycle. Most of an Olympic cyclist's energy is taken up in fighting wind resistance in a sprint. The first major innovation was the solid wheel, first used in competitive cycling in 1984, but originally patented as long ago as 1878. Further developments include handle bars that allow the cyclist to crouch and use the shape of the hands and forearms to divert air away from the chest. Modern racing bicycles now have a monocoque structure produced by laying carbon fiber around an internal mold and then baking them in an oven. Using all of these developments Chris Boardman set a speed record of 54.4 km/h (34 mph) on his way to winning a gold medal at the 1992 Barcelona Olympics.