At the heart of the 1951 NSU 125ZB sport motorcycle, NSU relies on a 123 cc (7.5 cu in) air-cooled single cylinder, two-stroke powerplant. 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.
The 8-liter (2.1 US gal) fuel tank supports practical everyday commuting and weekend road stints, while factory top speed is listed at 75 km/h (47 mph).
Within MotoLibrary's NSU archive, this model family spans 4 indexed model years from 1951 to 1954, 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.
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.
