Geoff Monty

[1][4][5] In the mid-1950s he produced and campaigned his own brand of racing motorcycle known as the "Geoff Monty Special" (GMS), based on his own design of semi-spine frame with rectangular-section swinging-arm and a 350 cc BSA Gold Star engine having modified internals to achieve a capacity slightly under 250 cc.

[7] Monty, in conjunction with his business partner Allen Dudley-Ward, a renowned Triumph tuner and ex-racer,[8] recognised a business opportunity and developed a new machine initially named Monward, based on his proven GMS frame and swinging-arm, initially fitted with a 650 cc Triumph Bonneville engine which was used as a test-bed by then-contracted rider, Bill Ivy.

[12] Both types of engine were tuned and built by Allen Dudley-Ward featuring his Manx Norton oil pump conversion.

[7] The now-oversquare modified engine used the 650 Bonneville twin-carb cylinder head having bigger valves, ports and carburettors than a standard Triumph 500, allowing for efficient air-fuel intake at racing speeds.

When track-testing the 500, Motorcycle Mechanics editor John Houslander reported that the engine would safely rev to 9,000 rpm making a potential 50 bhp and – with Isle of Man gearing and a four-speed gearbox – a top speed of 145 mph (233 km/h) was likely.