1957 BSA Golden Flash Technical Analysis & Specification Breakdown
Engineered by BSA for the allround motorcycle segment, the 1957 BSA Golden Flash utilizes a 646 cc (39.4 cu in) air-cooled twin, four-stroke layout. In factory specification, peak output is rated at 35 HP (25.5 kW) at 4,500 rpm, transferring power to the rear wheel through chain final drive. With a specific output of 54.2 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 Golden Flash measures 190 kg (419 lbs) dry, translating to a power-to-weight ratio of 0.18 HP/kg (5.43 kg per horsepower). The 19-liter (5 US gal) fuel tank supports practical everyday commuting and weekend road stints.
Within MotoLibrary's BSA archive, this model family spans 8 indexed model years from 1954 to 1961, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Use this page to compare this motorcycle by its real specifications, not only by model name. Focus on the details that affect fit, comfort, handling, range and ownership.
Power
Compare engine output with similar motorcycles if acceleration, highway use or two-up riding matters.
Weight
Compare weight carefully because it affects low-speed handling, parking and confidence.
Fuel Capacity
Fuel capacity helps estimate touring range and how often you may need to stop.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
