BSA B21250
 | |
| Manufacturer | BSA |
|---|---|
| Production | 1937 - 39 |
| Engine | Four stroke, single cylinder, Overhead valve |
| Ignition type | Magneto |
| Battery | 6V |
| Transmission | 4-Speed, hand change |
| Frame type | Triangulated cradle type |
| Suspension | Front: Girder, spring loaded fork Rear: None, spring loaded saddle |
| Wheelbase | 1575 mm / 62 in. |
| Fuel capacity | 13.6 L / 3.6 US gal |
| Oil capacity | 2.3 L / 4.8 US pints |
| Manuals | Service Manual |
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Chassis
The front suspension was a Girder, spring loaded fork while the rear was equipped with a None, spring loaded saddle. The B21250 was fitted with a 13.6 L / 3.6 US gal fuel tank. The wheelbase was 1575 mm / 62 in. long.
Photos
Overview
BSA B21
In the 1930s Birmingham's BSA was the world's most productive manufacturer, with a stretch of models between 150cc and 1000cc, produced in single cylinder and/or vee twin configurations. They enjoyed a particular strength in the quarter litre class, with a variety of side- and overhead valve models, offered in standard or de-luxe spec, one of the latter's options being foot-change gearbox operation.
Due to a disastrous attempt at the TT, back in the early 1920s, BSA deliberately avoided any forms of competition for the greater part of the Thirties, in complete contrast to their post war philosophy. Even so, in a contemporary magazine road test impression the B21 in question was reported to have 'peppy' performance and, "...contrary to its sturdy appearance was found surprisingly easy to manoeuvre on to the rear stand".
| Make Model | BSA B21 |
|---|---|
| Year | 1937 - 39 |
| Engine Type | Four stroke, single cylinder, Overhead valve |
| Displacement | 249 cc / 15.2 cub in |
| Carburetor | Amal |
| Oil Capacity | 2.3 L / 4.8 US pints |
| Exhaust | Single, chrome silencer |
| Ignition | Magneto |
| Battery | 6V |
| Starting | Kick starter |
| Transmission | 4-Speed, hand change |
| Final Drive | Chain |
| Gear Ratios | 1st 18.2 / 2nd 12.4 / 3rd 8.1 / 4th 6.2 |
| Frame | Triangulated cradle type |
| Front Suspension | Girder, spring loaded fork |
| Rear Suspension | None, spring loaded saddle |
| Wheelbase | 1575 mm / 62 in. |
| Ground Clearance | 124 mm . 4.9 in. |
| Fuel Capacity | 13.6 L / 3.6 US gal |
| Colour | Green or blue tank, black frame |
| Source | Bonhams |