A5KC New Bicycle Square Bottom Bracket Anti Drop Screw

Bicycles, also known as bicycles or bicycles, are usually small land vehicles with two wheels. After a person rides on a car, it is a green and environmentally friendly means of transportation that uses the pedals as power. English bicycle. Where bi means two, and cycle means wheel, that is, a two-wheeled vehicle. In Mainland China, Taiwan and Singapore, it is usually called "bicycle" or "bicycle"; in Hong Kong and Macau, it is usually called "bicycle" (in fact, Cantonese is usually called this); ". There are many types of bicycles, including single bicycles, tandem bicycles and multi-person bicycles. It can be used as an environmentally friendly means of transportation for walking and traveling; more and more people use bicycles as fitness equipment for exercise and bicycle travel; bicycles are also a sports competition, including road cycling, mountain bike racing, Track cycling, stunt cycling, etc. Among the 25 parts of the bicycle frame, tires, pedals, brakes, chains, etc., the basic parts are indispensable. Among them, the frame is the skeleton of the bicycle, and it bears the most weight of people and goods. According to the working characteristics of each component, it can be roughly divided into guiding system, driving system and braking system: