Abstract
A chain drive unit is an indispensable machine element in order to perform powerful and efficient action. It is used in various places of a world. However, in high-speed transmission like a motorcycle, there is a fault that a considerable vibration and noise generate. So, it aims at low noise-ization of the chain drive unit of a motorcycle in this research. If noise can be reduced, a chain drive unit will become a perfect transmission machine element. It thought that the noise problem that is an environmental problem was also solved. In the present day when traffic relations progressed, the bad influence (mental displeasure, hardness of hearing, mental disorder) that it has on the human body by the noise of a car and a motorcycle is so serious that it becomes an environmental problem. Therefore, it two aims at solutions of the improvement of the fault of a chain drive unit, and a noise problem. Low noise-ization of the chain drive unit of a motorcycle is aimed.
