The most popular bicycle model—and most popularvehicleof any kind in the world—is theChineseFlying Pigeon, with about 500 million produced.Classic bell of a bicycleAbicycle, also called acycleorbike, is ahuman-powered,pedal-driven,single-track vehicle, having twowheelsattached to aframe, one behind the other. Abicycle rideris called acyclist, or bicyclist.Bicycles were introduced in 
the late 19th century in Europe, and by the early 21st century, more than 1 billion have been produced worldwide.These numbers far exceed the number of cars, both in total and ranked by the number of individual models produced.They are the principalmeans of transportationin many regions. They also provide a popular form of recreation, and have been adapted for use as children's toys,general fitness, military and police applications,courier services,bicycle racingand bicycle stunts.The basic shape and configuration of a typicalupright or "safety bicycle", has changed little since the firstchain-drivenmodel was developed around 1885.But many details have been improved, especially since the advent ofmodern materialsandcomputer-aided design. These have allowed for a proliferation of specialized designs for many types ofcycling.The bicycle's invention has had an enormous effect on society, both in terms of culture and of advancing modern industrial methods. Several components that eventually played a key role in the development of the automobile were initially invented for use in the bicycle, includingball bearings,pneumatic tires,chain-driven sprocketsandtension-spoked wheels.
