NSU 251 OSL 1933 - Specifications & Review

In the realm of vintage motorcycles, few machines capture the spirit of early 20th-century sport biking quite like the 1933 NSU 251 OSL. As a product of NSU, a pioneering manufacturer from Germany, the 251 OSL stands out in the sport category for its innovative design and spirited performance. Introduced during a time when motorcycling was gaining traction as a thrilling pastime, this model embodies both the engineering advancements of its era and the aesthetic charm that classic motorcycle enthusiasts adore. With its distinctive lines and a minimalist, functional style, the 251 OSL is a testament to the craftsmanship and vision of the time.

At the heart of the NSU 251 OSL is a robust single-cylinder, four-stroke engine, boasting a displacement of 242cc that delivers a respectable 9 horsepower at 5,000 RPM. This power allows riders to reach a top speed of 100 km/h (62.1 mph), making it a spirited choice for both urban commuting and leisurely countryside rides. With a bore and stroke of 64.0 x 75.0 mm, the engine is tuned for smooth, reliable performance, while the 4-speed gearbox enables precise control over its power delivery. Coupled with an impressive fuel economy of 2.30 liters per 100 km, the 251 OSL promises to keep you on the road longer, allowing for more adventure with less frequent stops at the pump.

The technological features of the NSU 251 OSL showcase the forward-thinking design ethos of the early 1930s. It employs a traditional carburettor from either Amal or Graetzin, ensuring a straightforward fuel delivery system that enhances reliability. The motorcycle's open double steel frame contributes to its lightweight construction, tipping the scales at just 126 kg (277.8 lbs), while the drum brakes—both front and rear—provide effective stopping power for a confident riding experience. With a fuel capacity of 11.5 liters (3.04 gallons), riders can enjoy extended journeys, further complemented by the nostalgic kick starter that adds a touch of authenticity to the riding experience.

PROs:

1. Fuel Efficiency: With a consumption rate of just 2.30 liters per 100 km, the 251 OSL allows for extended rides without frequent refueling.
2. Lightweight Design: Weighing in at 126 kg, it’s easy to maneuver, making it an excellent choice for both new and experienced riders.
3. Classic Aesthetic: The vintage styling and engineering charm make it a standout piece for collectors and enthusiasts alike.

CONs:

1. Limited Power Output: At 9 HP, the engine may feel underpowered for those seeking high-performance capabilities.
2. Drum Brakes: While effective for the era, the drum brake system may not provide the stopping power expected by modern riders.
3. Kick Start Only: The absence of an electric start may deter some riders who prefer the convenience of modern starter systems.

In summary, the 1933 NSU 251 OSL is not just a motorcycle; it's a nostalgic journey back to the early days of motorcycling. For those who appreciate the blend of classic design, efficient performance, and a rich history, this model is a worthy addition to any collection.