Gbtme is a Decathlon brand bicycle. Yan value is very high, and it is still a big brand. I haven't seen it in a physical store before. Friends strongly recommend that children can't catch up with adults after riding, which shows that the quality is very good.

Principle of bicycle wheel

The principle of bicycle is that people's feet exert force on the pedal, so that the crank drives the sprocket to rotate, and the sprocket drives the flywheel to rotate through the chain, and then the flywheel rotates. Because of the friction between the rear wheel and the ground, the rear wheel will not slide relative to the ground, but roll on the ground, and the whole car will move.

Due to its own quality and self-weight, the wheel is uneven with the ground, and static friction will be generated when it is pressed on the road surface. When a person rides a bicycle, he presses the pedal hard to drive the sprocket behind him to rotate, and the bicycle begins to move. The static friction between the rear wheel and the ground is the same as the forward direction of the bicycle, so it pushes the bicycle forward.