1937

The first year for Valentine Page as chief designer. Almost all existing models were dropped and new models developed. This year BSA introduced the model groups: the B-group (light and middleweight motorcycles) and the M-group (middle and heavyweight motorcycles). Here the basis was formed for the famous models like the M20 and M24 Gold Star. Typical vintage design aspects like the separate push rod tubes, sump crankcases disappeared and were replaced by dry sump lubrication from a separate oil tank. They formed the foundation for postwar models like the B31 and B33 and the M20 and M21.

BSA 1937 models
Model	Description	Remarks
250 c.c. S .V. Tourer B20	B20 or 250 c.c. S.V. Tourer. The basic 249cc SV model with hand gear change.	black frame, green petrol tank.
250 c.c. O.H.V. Sports B21	B21 or 250 c.c. O.H.V. Sports. In spite of its name the basic 249cc OHV model with hand gear change.	black frame, chrome plated petrol tank with green panels.
250 c.c. O.H.V. Empire Star B22	B22 or 250 c.c. O.H.V. Empire Star, The 249cc OHV Empire Star model with foot gear change.	black frame, chrome plated petrol tank with Empire Star green panels. Chrome plated wheel rims. Low level exhaust system. Upswept exhaust pipe optional.
350c.c. S.V. Tourer B23	B23 or 350 c.c. S.V. Tourer. The 350cc SV model on offer with hand gear change.	black frame, chrome plated petrol tank with green panels.
350 c.c . O.H.V. Sports B26	B26 or 350 c.c. O.H.V. Sports. In spite of its name the basic 348cc OHV model with hand gear change.	black frame, chrome plated petrol tank with green panels.
350 c.c . O.H.V. Empire Star B24	B24 or 350 c.c. O.H.V. Empire Star. Sports model 348 cc OHV with air hardened cylinder optionally fitted with one or two upswept exhaust pipes.	black frame, chrome plated petrol tank with Empire Star green panels. Chrome plated wheel rims. Standard with low level exhaust system. Optionally fitted with upswept exhaust system. Two port head with upswept exhaust pipes extra.
350 c.c . O.H.V. Competition B25	B25 or 350 c.c. O.H.V. Competition. The 348cc OHV competition model based on the B24. with narrow round section mudguards, upswept exhaust pipe, 18" rear wheel and 21" front wheel and sunp protection plate. Also optionally fitted with two upswept exhaust pipes.	black frame, chrome plated petrol tank with green panels, chrome plated mudguards, chainguard, chaincase, high level exhaust system, 18" rear wheel and 21" front wheel fitted with Dunlop competition tyres. Two port head with upswept exhaust pipes extra.
350 c.c . O.H.V. de Luxe M19	M19 or 350 cc. O.H.V. de Luxe. Low capacity model for the M-group models, a 350cc OHV in very heavy cycle parts. "A medium-powered machine with a really good performance" according to BSA.	black frame, chrome plated petrol tank with green panels and instrument panel in petrol tank. Quickly detachable rear wheel.
500 c.c . S.V. Tourer M20	M20 or 500 c.c. S.V. Tourer. The first year of this standard 500cc SV model that would turn into a big seller because of World War II when it became one of the standard military models although it missed out on the first acceptance tests.	black frame, green petrol tank with instrument panel. Quickly detachable rear wheel.
500 c.c . O.H.V. Empire Star M23	M23 or 500 c.c. O.H.V. Empire Star. The new sporting 496cc OHV type with a familiar name although totally redesigned, with air hardened cylinder optionally fitted with one or two upswept exhaust pipes.	black frame, chrome plated petrol tank with Empire Star green panels. Chrome plated wheel rims with Empire Star green centres. Standard with low level exhaust system. Optionally fitted with upswept exhaust system. Two port head with upswept exhaust pipes extra. Quickly detachable rear wheel.
600 c.c. S.V. Tourer M21	M21 or 600 c.c. S.V. Tourer. The first year for another classic that was to remain well into the 1960s. The first year with a different bore and stroke (85 x 105 = 595 cc).	black frame, green petrol tank with instrument panel. Quickly detachable rear wheel.
500 c.c. O.H.V. Sports M22	M22 or 500 c.c. O.H.V. Sports. The 496cc OHV model for either solo riding or sidecar duty.	black frame, chrome plated petrol tank with green panels and instrument panel in petrol tank. Two port head with upswept exhaust pipes extra. Quickly detachable rear wheel.
750 c.c . O.H.V. Vee-Twin Y13	Y13 or 750 c.c. O.H.V. Vee-Twin. This spectacular 750 cc OHV V-twin survived the Val Page storms together with G14. Almost identical to the 1936 version.	black frame, chrome plated petrol tank with green panels, instrument panel in tank. Quickly detachable and interchangeable wheels.
9.86 h.p. Vee-Twin G14	G14 or 1,000 c.c. Vee-twin. The 986cc sidevalve V-twin still with total loss lubrication now looking seriously obsolete compared to the dry sump Val Page models.	black frame, chrome plated petrol tank with green panels, instrument panel in tank. Quickly detachable and interchangeable wheels but still with hand change.