4G Square Four 1000

1940 Ariel 4G Square Four 1000 Technical Analysis & Specification Breakdown

Engineered by Ariel for the allround motorcycle segment, the 1940 Ariel 4G Square Four 1000 relies on a 997 cc (60.8 cu in) air-cooled square four cylinder powerplant. In factory specification, peak output is rated at 35 HP (25.5 kW) at 5,500 rpm, transferring power to the rear wheel through a 4-speed gearbox and chain final drive. With a specific output of 35.1 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 4G Square Four 1000 measures 193 kg (425 lbs) dry, translating to a power-to-weight ratio of 0.18 HP/kg (5.51 kg per horsepower). Rider ergonomics and chassis geometry center around a 1,422 mm (56 in) wheelbase engineered for balanced agility and highway composure. The 23-liter (6.1 US gal) fuel tank supports practical everyday commuting and weekend road stints, while factory top speed is listed at 140 km/h (87 mph).

Within MotoLibrary's Ariel archive, this model family spans 14 indexed model years from 1936 to 1949, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.