KH 500 Fieldmaster

1957 Ariel KH 500 Fieldmaster Technical Analysis & Specification Breakdown

Engineered by Ariel for the allround motorcycle segment, the 1957 Ariel KH 500 Fieldmaster features a 498 cc (30.4 cu in) air-cooled twin, four-stroke configuration. In factory specification, peak output is rated at 28 HP (20.5 kW) at 6,500 rpm, transferring power to the rear wheel through a 4-speed gearbox and chain final drive. With a specific output of 56.2 HP per liter, the engine character is prioritizing low-RPM tractability, mechanical longevity and relaxed throttle response over peak redline numbers.

On the scales, the KH 500 Fieldmaster measures 177 kg (390 lbs) dry, translating to a power-to-weight ratio of 0.16 HP/kg (6.32 kg per horsepower). Rider ergonomics and chassis geometry center around a 787 mm (31 in) seat height — offering a neutral standover height that accommodates most average-inseam riders without sacrificing cornering clearance, combined with a 1,422 mm (56 in) wheelbase engineered for balanced agility and highway composure. The 17-liter (4.5 US gal) fuel tank paired with a rated consumption of 3.04 L/100 km provides an estimated theoretical range of roughly 559 km (347 miles) between fill-ups, while factory top speed is listed at 145 km/h (90 mph).

Within MotoLibrary's Ariel archive, this model family spans 2 indexed model years from 1956 to 1957, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.