The Sunbeam Model B1 scooter was produced between 1957 and 1964, featuring a parallel twin cylinder, 4 stroke engine with a capacity of 250 cc. The bike had a forced air cooling system and a compression ratio of 6.5:1, along with a 12V battery and electric starting. The maximum power output was 7.5 kW or 10 hp at 5500 rpm. The bike had a four-speed transmission and enclosed chain final drive, sitting on a tubular frame with a ground clearance of 127 mm. The front and rear brakes were both drums with a diameter of 127 mm. The bike’s tires were 3.50 x 10 inches, and the dry weight was 110 kg or 243 lbs. The fuel consumption was stated to be 2.4 L/1000 km or 41.7 km/l, which translates to 118 Imp mpg or 98 US mpg. The top speed of the bike was reported to be 97 km/h or 60 mph.
Technical specifications:
Make Model: Sunbeam B1
| Year | 1957 – 64 |
|---|---|
| Engine | Parallel twin cylinder, 4 stroke |
| Capacity | 250 cc / 15.3 cu in |
| Bore x Stroke | 56 x 50.6 mm |
| Cooling System | Forced air cooled |
| Compression Ratio | 6.5:1 |
| Battery | 12V |
| Starting | Electric |
| Max Power | 7.5 kW / 10 hp @ 5500 rpm |
| Transmission | Four speed |
| Final Drive | Enclosed chain in oil bath |
| Frame | Tubular frame |
| Ground Clearance | 127 mm / 5.0″ |
| Front Brakes | Drum, 127 mm diameter |
| Rear Brakes | Drum, 127 mm diameter |
| Tyres, Front and Rear | 3.50 x 10″ |
| Dri weight | 110 kg / 243 lbs |
| Fuel Consumption | 2.4 L/1000 km/ 41.7 km/l / 118 Imp mpg / 98 US mpg |
| Top Speed | 97 km/h / 60 mph |
