1991-1994 588cc Duckhams Crighton Norton

Based in Australia during 1991, Brian Crighton's breakaway Roton team made a strong impression, winning a national Superbike race and taking 15th place in the nation's GP with Steve Spray in the saddle. In 1992, Crighton fielded his rotaries in the UK and by mid-season he had gained backing from the Duckhams oil brand. The Crighton Norton team manged by Colin Seeley recruited Mark Farmer as rider and began getting results to outshine the fading JPS team, whih withdrew at the end of the year.

Over the next two seasons, Duckhams Crighton Nortons achieved a fantastic run of Superbike successes against the toughest possible opposition on UK circuits. Farmer moved on and his replacement Jim Moodie took second and third places in major 1993 championships. For 1994, the team riders were Phil Borley amd Ian Simpson, who both rode brilliantly to rack up no fewer that 52 hard-fought rostrum finishes, with Simpson clinching ultimate victory in the 1994 HEAT British Supercup series.

Based on the Roton machine, the Crighton Norton has a twin-spar aluminium Sppondon frame with the twin shock type of rear suspension preferred by Crighton. Engine development had raised output to 150 hp, transmitted via a six-speed close-ratio gearbox and weight was pared down to below 300lb. The Crighton Nortons retired at the end of 1994, while they were still the fastest in their class.