Y13

1937 BSA Y13 Technical Analysis & Specification Breakdown

Engineered by BSA for the cross - motocross motorcycle segment, the 1937 BSA Y13 pairs a 748 cc (45.6 cu in) air-cooled twin, four-stroke architecture with road-focused gearing. In factory specification, peak output is rated at 19.5 HP (14.2 kW) at 4,800 rpm, transferring power to the rear wheel through chain final drive. With a specific output of 26.1 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 Y13 measures 204 kg (450 lbs) wet (curb), translating to a power-to-weight ratio of 0.1 HP/kg (10.46 kg per horsepower). Rider ergonomics and chassis geometry center around a 1,372 mm (54 in) wheelbase engineered for quick, flickable steering geometry. The 17-liter (4.5 US gal) fuel tank supports practical everyday commuting and weekend road stints.

Within MotoLibrary's BSA archive, this model family spans 3 indexed model years from 1936 to 1938, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.