sentences:  As of 2013 the championship is organised by Dorna.The Superbike World Championship began in , being open to modified versions of road bike models available to the public.For many years, the formula allowed for machines with 1,000 cc V-twin engines (principally Ducati, but later Aprilia and Honda) to go up against the 750 cc four-cylinder engines (Honda, Yamaha, Kawasaki and Suzuki).