A control unit made throttle adjustments to keep the engine speed matched to the driven clutch plate and also varied the speed of clutch operation appropriate to road speed. (en.wikipedia.org)
Some motorcycles also use a system with a conventional gear change but without the need for manual clutch operation. (en.wikipedia.org)
All shades come standard with straight bottoms and heavy duty continuous chain clutch operation. (ocwindowshades.com)