The first clutch is an advanced kind of centrifugal clutch and is often mounted to the output stop from the engine crankshaft. The clutch has two sheave faces; one that is laterally fixed (stationary sheave), and one that can shift out and in to engage the belt (moveable sheave). https://gearbox-cvt22085.myparisblog.com/32865389/detailed-notes-on-cvt