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BSA A

Make Model	BSA A
Year	1921 - 24
Engine	Four stroke, V-twin cylinder, side valve
Capacity	770 cc / 50 cub in
Bore and Stroke	76 x 85 mm
Lubrication	Constant loss oil pump supplemented by hand operated pump
Exhaust	Single, stainless steel
Ignition	Magneto
Battery	6V
Starting	Slip on kick starter
Max Power	4.4 kW / 6 hp
Transmission	3-Speed
Final Drive	Chain
Front Suspension	Single spring girder fork
Rear Suspension	None, spring loaded saddle
Top speed	88 km/h / 55 mph
Colour	Green and cream tank/black frame

After having been turned over to weapons production for World War I, BSA returned to producing motorcycles again which were sold as affordable with reasonable performance for the average user. BSA stressed the reliability of their machines, the availability of spares and dealer support. The BSA Model E was the first of a series of successful V-twins based around the reliable 770cc side valve engine with cylinders at an angle of 50 degrees. The modest 6hp produced by the engine was able to provide a top speed of 55mph and it had BSA's own design of three speed gearbox with the drive chain enclosed in an aluminium casing. There was an increased demand for affordable transport after the end of the war and the Model E became popular with BSA's matching green and cream painted sidecar option.

Designed for easy servicing the valves were interchangeable and had quickly adjustable tappets. The constant loss oil pump was supplemented by a hand operated pump and the wheels were also quickly detachable and the same size so that they were interchangeable.

Although the BSA Model E was produced until 1924 it had been largely replaced by the more powerful 986cc Model F in 1922, which continued in production as the BSA Model G, with continual modifications, until just after the outbreak of World War II.

Between 1920 and 1925 BSA produced a 100 small three-wheeled taxi cabs using the Model E 770cc V twin engine.