| Attribute | Simson 425 GS 1957 × | AJS Model 14 250 1965 × |
|---|---|---|
| General | ||
| Production from (year) | 1957 | 1965 |
| Make | Simson | AJS |
| Model | Simson 425 GS | AJS Model 14 250 |
| Category | Sport | Sport |
| Engine and transmission | ||
| Engine type | Single cylinder, four-stroke | Single cylinder, four-stroke |
| Fuel system | Carburettor | Carburettor |
| Displacement (cm³) | 247 | 248 |
| Power (kw) | 12.8 | 12.4 |
| Fuel consumption (l/100km) | 3.3 | - |
| Cooling system | Air | Air |
| Transmission type,final drive | Shaft drive (cardan) | Chain |
| Bore (mm) | 68 | 69.9 |
| Stroke (mm) | 68 | 64.9 |
| Greenhouse gases | 76.6 CO2 g/km. (CO2 - Carbon dioxide emission) | - |
| Fuel control | - | Overhead Valves (OHV) |
| Ignition | Magneto | - |
| Clutch | - | Wet multiplate |
| Compression | - | 7.8:1 |
| Chassis | ||
| Front suspension | Telescopic | Telescopic |
| Rear suspension | Swingarm | Swingarm-two shocks |
| Front brakes | Expanding brake (drum brake) | Expanding brake (drum brake) |
| Rear brakes | Expanding brake (drum brake) | Expanding brake (drum brake) |
| Diameter (mm) | 180 | 152 |
| Frame type | - | Open tubular steel |
| Front tyre | 3.5-19 | 3.25-17 |
| Rear tyre | 4-18 | 3.25-17 |
| Seat | Single | Dual |
| Wheels | - | Spoked |
| Other | ||
| Starter | - | Kick |
| Dimensions | ||
| Dry weight (kg) | 157 | 149 |
| Power/weight ratio | 0.0815 | 0.0832 |
| Performance | ||
| Fuel capacity (l) | 16 | 12.5 |