Bicycles, also known as bicycles or bicycles, are usually small land vehicles with two wheels. After riding the car, it is a green and environmentally friendly vehicle driven by stepping on the pedal. In Mainland China, Taiwan and Singapore, they are often referred to as "bicycles" or "bicycles"; In Hong Kong and Macao, it is usually called "bicycle" (in fact, it is usually called in Cantonese); In Japan, it is called "self transfer". There are many kinds of bicycles, including single-person bicycles, double-person bicycles and multi-person bicycles.

Bicycle is one of the best tools for sports and leisure activities. Kinematics experts believe that cycling, like running, walking and swimming, can exercise the endurance of internal organs and improve the heart and lung function. Because riding a bicycle is a heterolateral dominant movement, the alternating pedaling of two legs can also make the brain functions of the left and right sides develop in a balanced and coordinated manner, thus improving the agility of the nervous system. It is understood that there are 20 million people riding bicycles to exercise in the United States today; In Europe, cycling "one-day tour" has also become one of the most fashionable sports.