The primary clutch is an advanced form of centrifugal clutch and is typically mounted into the output close of the engine crankshaft. The clutch has two sheave faces; one which is laterally fastened (stationary sheave), and one which can shift out and in to engage the belt (moveable sheave). https://gearbox-cvt20853.blog4youth.com/32937240/helping-the-others-realize-the-advantages-of-cvt