04-18 YAMAHA YZF-R1: Yoshimura Axle Adjuster Blocks (Works Edition) Anyone who has tried to adjust their chain with O.E.M.-style axle adjuster blocks knows the frustration of dealing with sub-par quality. These Yoshimura units are lighter weight, more accurate, stronger than the factory ones, and they look great too!Laser-etched logo.CNC-machined from aircraft-grade billet 6061-T6 aluminum.Lighter and stronger than stock.Anodized finish.Reversible for larg