Sichuan Kangruntengpu Photoelectric Technology Co., Ltd. , https://www.kangruntoplighting.com The structure of the bicycle pump is simple, and the inner surface roughness of the gas cylinder is not strict. However, it is sealed with a cup. When installing the cup, it must be soaked with mechanical oil to soften it. Therefore, when it takes a long time, it will gradually dry and become hard, and the lip will be prone to cracks, which will affect the sealing performance and prevent air intake. If you use two O-rings to improve the cylinder piston, you can overcome the disadvantages of the cup.