YAMAHA XJ N /XJ S DIVERSION (4BRA,4BRB/F944/945) 600CC model year 1991-1997. YAMAHA XJ N /XJ S DIVERSION (RJ01/H810) 600CC model year 1998-2003. WHEEL RIM HUB. The shape of the disc ensures good heat dissipation under heavy braking sessions, reducing brake fade, minimising warping, and ensuring rotor longevity.