Positioned in Hercules's sport motorcycle lineup, the 1951 Hercules 311 utilizes a 123 cc (7.5 cu in) air-cooled single cylinder, two-stroke layout. In factory specification, peak output is rated at 5 HP (3.6 kW) at 5,000 rpm, transferring power to the rear wheel through chain final drive. With a specific output of 40.7 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 311 measures 90 kg (198 lbs) dry, translating to a power-to-weight ratio of 0.06 HP/kg (18 kg per horsepower).
Within MotoLibrary's Hercules archive, this model family spans 4 indexed model years from 1950 to 1953, 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.
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.
