Today in Motorcycle History

NSU SuperMax 250cc (Type 251 OSB)

The Supermax was derived from the Max and Spezialmax but differed in many areas, the most obvious being the rear suspension. Commanding considerable esteem both in Germany and abroad, it was a high performance machine with excellent reliability.

Manufacturing Dates: Late 1956 to 1963
Production Figures:

    1956: 4440
    1957: 2563
    1958: 2357
    1959: 1403
    1960: 2619
    1961: 1240
    1962: 473
    1963: 378


Engine: single-cylinder four-stroke, dry sump with external oil tank and Micronic paper oil filter
Power: 18hp at 6900 rpm
Displacement: 247 cc
Bore x stroke: 69 mm x 66 mm
Compression ratio: 7.4:1
Spark plugs: W 240 T11, gap: 0.7 mm
Valvetrain: OHC, camshaft driven by Ultramax rods, hairpin-style valve springs
Carburetor: BING 2/26/55
Transmission: 4 speed
Frame: pressed metal

Brakes: drum front and rear
Tyres size: 3.25 x 19in front and rear
Unladen Weight: 174 kg
Maximum weight: 315 kg
Length: 2051 mm
Fuel tank capacity: 14 ltr
Oil tank capacity: 2 ltr
Fuel consumption: 3.2 ltr/100 km
Top speed: 126 km/h
Suspension: Leading link front forks and swinging arm rear suspension with dual shock absorbers (earlier models had a mono arrangement.

Information on this page based on work by Hartmut Schouwer