The goal was to produce a motorcycle with 500 cc displacement that was able to develop 60 hp and have 13-second quarter-mile times, then considered over the achievable limit for a road bike.

[2] When announced, the H1 was critiqued in UK motorcycling press for their "own ambitious claim" of "the fastest and best accelerating road machine ever produced, being capable of 124 mph and 12.4 sec.

It had Mikuni VM 28 mm carburetors, and thyristor-based capacitor discharge ignition (CDI) developing 25,000–30,000 volts.

The gearbox was odd, with neutral below first, the brakes very questionable and the handling decidedly marginal in every situation - except when the bike was stopped with the engine switched off.

H1R derivatives of the Mach III were raced by Ginger Molloy in Grands Prix, his "Green Meanie" finishing 2nd just behind Giacomo Agostini's MV Agusta in the 1970 500 cc World Championship,[10] and by UK riders Paul Smart and Cliff Carr in Europe and North America.