The bicycle pump has two air nozzles.

1. There is a pin in the inflation hole, and only when the pin is pressed can it be ventilated, which is a bit like a piston.

2. Only when there is airflow, the suture will be pushed away, so that it can be restarted in the tire. When there is no air, it is closed.

3. According to these two principles, it can be guaranteed that he can only ventilate if the pipe on one side is inserted into the rim to inflate.

Yes, that is, the pillar in the middle must be pressed to prevent air leakage.

1. There are generally two kinds of valves for tires.

2. The pump also has two kinds of air nozzles. When pumping air, try two holes.

3. If you press hard and find gas coming out, you can immediately press the back one to find a suitable gas nozzle to inflate.

4. At present, the common bicycle inner tire valves in the field of bicycle valves in China are mainly divided into three categories: English valve (English valve); American gas nozzle (American nozzle); French gas nozzle (French nozzle).