Sunbeam Model B1 scooter (1957-64)

Posted on by

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

Related models: