Make Model



1921 - 24


Four stroke, V-twin cylinder, side valve


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



Final Drive

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.