Attribute | ![]() BMW R39 1926 × | ![]() NSU 251 OSL WH 1938 × |
---|---|---|
General | ||
Production from (year) | 1926 | 1938 |
Make | BMW | NSU |
Model | BMW R39 | NSU 251 OSL WH |
Category | Naked bike | Allround |
Engine and transmission | ||
Engine type | Single cylinder, four-stroke | Single cylinder, four-stroke |
Fuel system | Carburettor. 20mm BMW Spezial | Carburettor. Amal |
Displacement (cm³) | 247 | 242 |
Power (kw) | 4.4 | 7.7 |
Cooling system | Air | Air |
Transmission type,final drive | Shaft drive (cardan) | Chain |
Bore (mm) | 68 | 64 |
Stroke (mm) | 68 | 75 |
Gearbox | 3-speed | - |
Fuel control | Overhead Valves (OHV) | - |
Clutch | Dry-single plate-cable operated | - |
Lubrication system | Wet sump | - |
Compression | 6.1:1 | - |
Chassis | ||
Front suspension | Leading link | - |
Rear suspension | Rigid | - |
Front brakes | Expanding brake (drum brake) | Expanding brake (drum brake) |
Rear brakes | - | Expanding brake (drum brake) |
Frame type | Steel doble cradle | Steel |
Front tyre | 3.5-27 | 3-19 |
Rear tyre | 3.5-27 | 3-19 |
Seat | Single seat | Single |
Wheels | - | Spoked |
Other | ||
Starter | Kick | Kick |
Dimensions | ||
Kerb weight (kg) | 110 | - |
Dry weight (kg) | - | 144 |
Power/weight ratio | - | 0.0535 |
Overall height (mm) | 950 | 950 |
Overall length (mm) | 2,050 | 2,040 |
Overall width (mm) | 800 | 780 |
Performance | ||
Top speed (km/h) | 100 | 95 |
Fuel capacity (l) | - | 11 |