The first step Rollmaster took in creating the world's best chain and sprocket system was to utilize billet steel construction for the upper and lower sprockets rather than cast iron. This reduced wear and improved accuracy by providing 100% CNC machined Surfaces. Next Rollmaster determined that the easiest, most accurate and dependable method for providing adjustability in cam timing was to provide nine keyway positions on most lower sprockets. This eliminated the need for offset bushings and proved much more reliable and positive than adjustable eccentric style pins or multi part upper sprockets. Nine keyways were not possible until Rollmaster produced the lower sprocket from billet steel. Cast iron simply cannot provide the strength necessary when material thickness and mass are reduced by the keyways. Billet can provide the strength and has proven so for 36 years