Engineered by Lambretta for the scooter motorcycle segment, the 1949 Lambretta 125B features a 123 cc (7.5 cu in) air-cooled single cylinder, two-stroke configuration. In factory specification, peak output is rated at 4.1 HP (3 kW) at 4,500 rpm, transferring power to the rear wheel through a 3-speed gearbox. With a specific output of 33.3 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 125B measures 54.9 kg (121 lbs) dry.
Within MotoLibrary's Lambretta archive, this model family spans 4 indexed model years from 1948 to 1951, 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.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
