The first clutch is an advanced kind of centrifugal clutch and is typically mounted on the output end in the motor crankshaft. The clutch has two sheave faces; one that is laterally set (stationary sheave), and one that can go out and in to engage the belt (moveable sheave). https://gearbox-cvt20752.webdesign96.com/32877739/gearbox-cvt-things-to-know-before-you-buy