A Study of Dry Centrifugal Clutch Judder

Dry centrifugal clutches used in conventional scooters occasionally suffer from judder, a problem that is extremely time consuming and expensive to solve.

In order to study the judder phenomena, an experimental analysis was performed on a 125cc scooter. Numerical simulations were also performed to verify the experimental analysis results and to elucidate the principle of the judder.

The results of this analysis show that dry centrifugal clutch judder can be modeled as torsional self-exited vibration of the drive train caused by the friction characteristics of the clutch, and that tire characteristics are also a contributing factor. These results correspond to previous experimental findings and countermeasures.