Folding bike Frame&fork:aluminium alloy Steel handlebar 14GCP spoke 48T chainwheel Black&silver brake cable Shimano 6 speed freewheel Shimano rear derailleur Shimano index gripshifter Alloy hub T-stem:aluminium alloy Crank:aluminium alloy Brake:the former clamp after brake Dia of tyre:16" Folding bike pedals Surface treatment:polish or coated折叠自行车车架，车叉：铝合金 钢车把 14GCP以 48T链 黑与银色刹车线 西玛诺6速飞轮 西玛诺后避震 西玛诺指数gripshifter 合金枢纽 T型干：铝合金 曲柄：铝合金 刹车：前制动钳后的轮胎直径： 16 “ 折叠自行车踏板 表面处理：抛光或涂层
bicycle, cycle, or bike is a pedal-driven, human-powered vehicle with two wheels attached to a frame, one behind the other.
Bicycles were introduced in the 19th century and now number about one billion worldwide.[1] They are the principal means of transportation in many regions. They also provide a popular form of recreation, and have been adapted for such uses as children's toys, adult fitness, military and police applications, courier services, and competitive sports.
The basic shape and configuration of a typical bicycle has changed little since the first chain-driven model was developed around 1885.[2] Many details have been improved, especially since the advent of modern materials and computer-aided design. These have allowed for a proliferation of specialized designs for particular types of cycling.
The bicycle has had a considerable effect on human society, in both the cultural and industrial realms. In its early years, bicycle construction drew on pre-existing technologies; more recently, bicycle technology has, in turn, contributed both to old and new areas.
