In recent years, rear suspension systems with a single shock absorber unit placed behind the engine, have been used primarily in the middle and large classes of motorcycles.
Some features such as the longer rear wheel travel, progressive response characteristics and mass concentration at the center part of motorcycle are effective in improving maneuverability of the motorcycle.
In the 1980s, the systems were introduced first in the off-road motorcycles and then in the on-road motorcycles. Performance of the systems are excellent, but there are demands for further improvement of suspension characteristics and space utility at the center part of motorcycle.
For this purpose, we have developed a prototype of a rotary shock absorber and studied the applicability to modern motorcycles.