| MODEL | BSA C12 250 1956 - 1958 |
| Year | 1956 - 1958 |
| Engine Type | Four stroke, single cylinder, OHV |
| Displacement / Capacity | 249 cc / 15.2 cu in |
| Bore X Stroke | — |
| Compression Ratio | — |
| Cooling System | Air cooled |
| Max Power | 9 kW / 12 hp |
| Max Torque | — |
| Ignition | Coil |
| Induction | Amal carburettor |
| Start System | Kick start |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 4-Speed |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Brazed lug construction |
| Front Suspension | Telescopic with compression damping, 152 mm / 6 in travel |
| Rear Suspension | Swinging arm, 62 mm / 2.45 in travel |
| Front Brakes | 7 in drum |
| Rear Brakes | 5.5 in drum |
| DIMENSION SPECS | |
| Overall Length | 2083 mm / 82.0 in |
| Overall Width | 673 mm / 26.5 in |
| Overall Height | 1016 mm / 40.0 in |
| Seat Height | 749 mm / 29.5 in |
| Wheelbase | 1372 mm / 54 in |
| Ground Clearance | 102 mm / 4 in |
| Dry Weight | — |
| Wet Weight | 145 kg / 320 lbs |
| WHEEL SPECS | |
| Front Tyre | 3.00 x 19 in |
| Rear Tyre | 3.00 x 19 in |
| FUEL SYSTEM | |
| Fuel Capacity | — |
| Fuel Consumption | 2.9 L/100 km / 80 US mpg |
| Top Speed | 113 km/h / 70 mph |
The C12 replaced the C11G in 1956 and kept its 249 cc overhead-valve engine and four-speed gearbox, but put them in a newer swinging-arm chassis. It was the last of the pre-unit BSA 250s and was superseded by the unit-construction C15 in 1958.
