| MODEL | SUNBEAM B1 1959 - 1964 |
| Year | 1959 - 1964 |
| Engine Type | Parallel twin, four-stroke |
| Displacement / Capacity | 250 cc / 15.3 cu in |
| Bore X Stroke | 56 x 50.6 mm |
| Compression Ratio | 6.5:1 |
| Cooling System | Forced air |
| Max Power | 7.5 kW / 10 hp @ 5500 rpm |
| Max Torque | — |
| Ignition | — |
| Induction | — |
| Start System | Electric (12V) |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 4-speed |
| Clutch | — |
| Final Drive | Enclosed chain in oil bath |
| CHASSIS SPECS | |
| Frame | Tubular |
| Front Suspension | — |
| Rear Suspension | — |
| Front Brakes | Drum, 127 mm |
| Rear Brakes | Drum, 127 mm |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | 127 mm / 5.0 in |
| Dry Weight | 110 kg / 243 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.50 x 10 in |
| Rear Tyre | 3.50 x 10 in |
| FUEL SYSTEM | |
| Fuel Capacity | — |
| Fuel Consumption | 2.4 L/100 km / 118 Imp mpg / 98 US mpg |
| Top Speed | 97 km/h / 60 mph |
The B1 was the larger of two scooters BSA marketed under the Sunbeam name, powered by a forced-air-cooled 250 cc four-stroke twin with an electric starter. It had a four-speed foot-operated gearbox and an enclosed chain running in oil, aimed at the touring commuter rather than the sports rider. It was built from late 1959 and dropped in 1964.
