BSA Rocket 3/Triumph Trident adaptations only, available from the factory as part-numbered inventory. Williams' team won consecutive 750 cc production races at the Isle of Man TT for the five years between 1971 and 1975, and in the new F750 event for race-specification machines, Triumph and BSA machines with Rob North frames placed first and second. Bert Hopwood recommended a production version of the racing triple, producing at 8,250 rpm, but his suggestion was not adopted. Further racing development was done in Duarte, California under racing manager Dan Macias. Tom Mellor set four world speed records at the Bonneville Salt Flats in September 2008
Triumph Model H Model H was fitted with a 499 cc air-cooled four-stroke single-cylinder engine. It was also the first Triumph not to be fitted with pedals, so was a true motorcycle. Engine differences from the previous Model A included a single cam wheel with two cams replacing separate cam wheels for the inlet and exhaust valve, and new design of cylinder casting. Valve head diameter was enlarged and the valves were spaced further apart. The Model H was fitted with a Sturmey-Archer three-speed countershaft gearbox operated by a hand gear change lever. More than 30,000 Triumph Model H motorcycles had been produced