NSU 251 OSL 1935 - Specifications & Review

Introducing the 1935 NSU 251 OSL: A Sporty Classic with Timeless Charm

The 1935 NSU 251 OSL stands as a remarkable testament to the early days of motorcycle engineering, combining spirited performance with elegant design. This sport-oriented motorcycle was crafted by NSU, a pioneering German manufacturer, renowned for its innovative approach during a time when the motorcycle industry was rapidly evolving. The 251 OSL is not just a piece of history; it is a symbol of the pre-war era, attracting collectors and vintage enthusiasts alike with its distinctive silhouette and reliable performance. Its lightweight frame and responsive handling make it an engaging ride for those who appreciate the art of motorcycling.

At the heart of the NSU 251 OSL lies a robust 242cc single-cylinder, four-stroke engine, delivering a respectable 9 horsepower at 5,000 RPM. This powertrain is coupled with a smooth 4-speed gearbox, allowing riders to seamlessly navigate through various terrains and conditions. With a top speed of 100 km/h (62.1 mph), the 251 OSL maintains a spirited pace that is both thrilling and accessible, making it a joy to ride on winding country roads or city boulevards. Perhaps most impressive is its fuel efficiency, boasting a remarkable 2.30 litres per 100 km (102.27 mpg), allowing for extended rides without frequent stops at the pump.

The NSU 251 OSL is equipped with features that reflect the advanced engineering of its time. Its open double steel frame provides a rigid yet lightweight foundation, enhancing maneuverability while ensuring stability. The drum brakes, both front and rear, offer reliable stopping power, although they require a more engaged approach compared to modern hydraulic systems. The bike's air-cooling system allows for optimal temperature management during rides, while the Amal or Graetzin carburettor ensures a consistent fuel-air mixture for smooth acceleration. The kick starter adds a touch of nostalgia, embodying the essence of classic motorcycling where the rider and machine share a more hands-on connection.

Pros:

1. Lightweight Construction: At just 126 kg (277.8 lbs), the 251 OSL is nimble and easy to handle, making it perfect for both novice and experienced riders.
2. Outstanding Fuel Efficiency: With an impressive consumption rate of 2.30 litres/100 km, this motorcycle allows for long journeys without the need for frequent refueling.
3. Timeless Design: The classic aesthetics and historical significance of the NSU 251 OSL make it a standout piece for collectors and vintage motorcycle enthusiasts.

Cons:

1. Limited Power Output: The 9 HP may feel modest compared to modern motorcycles, which can limit performance on highways or steep inclines.
2. Drum Brakes: While effective for their time, the expanding drum brakes may not provide the same level of stopping power or responsiveness as contemporary disc brakes.
3. Kick Starter Only: The absence of an electric start can be a drawback for some riders, particularly in challenging weather or for those less familiar with kick starting techniques.

In summary, the 1935 NSU 251 OSL offers a captivating blend of nostalgia, efficiency, and sport-oriented performance, making it a cherished model for vintage motorcycle aficionados. Whether you're taking it for a spin or showcasing it in your collection, this classic bike embodies the spirit of early motorcycling adventures.