This motorcycle requires 2x of the above item(s). ‘The Silent Chain manufactured by Borg-Warner Automotive, Japan is the world’s quietest and most efficient. It is manufactured with technology derived from the Morse® Hy-Vo® chain, First developed by Borg-Warner Automotive, U.S.A. Reacting to customers ever-changing and demanding requirements, we have reduced noise and weight, and increased durability, together with the ability to withstand high revolutions. Solving many of the problems inherent in the usual bushed chain, belt and gear drives. We have a firm policy of ongoing development, in pursuit of a more reliable silent chain. We are sure that you will be satisfied after using our silent chain.' - Borg-Warner Automotive