BSA B31350
It could reach a top speed of 110 km/h / 70 mph.
BSA B31350 | |
Manufacturer | |
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Production | 1945 - 59 |
Engine | Four stroke, single cylinder, Overhead valve |
Compression ratio | 6.5:1 |
Top Speed | 110 km/h / 70 mph |
Ignition | Lucas magneto MO1L |
Transmission | 4-Speed manual |
Suspension | Front: Hydraulic fork Rear: Swinging arm fork with shocks |
Front Tire | 3.25 x 19 in. Dunlop Gold Seal |
Rear Tire | 3.5 x 19 in. Dunlop Gold Seal |
Weight | 175 kg / 385 lbs (wet) |
Fuel Capacity | 19 L / 5 US gal |
Manuals | Service Manual |
Engine
The engine was a Air cooled cooled Four stroke, single cylinder, Overhead valve. The engine featured a 6.5:1 compression ratio.
Drive
Power was moderated via the Multi-plate.
Chassis
It came with a 3.25 x 19 in. Dunlop Gold Seal front tire and a 3.5 x 19 in. Dunlop Gold Seal rear tire. The front suspension was a Hydraulic fork while the rear was equipped with a Swinging arm fork with shocks. The B31350 was fitted with a 19 L / 5 US gal fuel tank.
Photos
Overview
BSA B31
The BSA B31, introduced in 1945, was the first new model introduced by the company after the Second World War. Based on pre-war designs, it used a single cylinder four stroke engine that displaced 348 cc (21.2 cu in). Initially, it had a rigid frame and telescopic forks, the first use of such on a BSA. It developed about 17 bhp (13 kW), adequate for the roads of the day and enough to deliver a top speed of around 70 mph (110 km/h). It was immediately popular and was soon joined by a 500 cc (31 cu in) version, the BSA B33 and competition equivalents, the BSA B32 and BSA B34; the side-car version, with stiffer suspension and different final demultiplication, was known as BB31.
Plunger rear suspension was offered later, with a swingarm rear suspension frame available from 1954. The model continued in production until 1959, by which time the traditional Lucas magdyno had been replaced by an alternator and coil ignition.
The B series expanded through its life to include the famous BSA Gold Stars, and the bottom half of all engines has much in common with the M series side valve models. The M33, designed for sidecar work, combined the strong M series frame and the better-performing B33 500 cc overhead valve engine.
Make Model | BSA B31 |
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Year | 1945 - 59 |
Engine Type | Four stroke, single cylinder, Overhead valve |
Displacement | 348 cc / 21.2 cub in. |
Bore X Stroke | 71 x 88 mm |
Compression | 6.5:1 |
Cooling System | Air cooled |
Lubrication | Dry sump |
Exhaust | Single, stainless steel and chrome |
Carburetor | Single Amal type 76 |
Ignition | Lucas magneto MO1L |
Starting | Kick start |
Clutch | Multi-plate |
Maximum Power | 16.2 kW / 22 hp @ 6000 rpm |
Transmission | 4-Speed manual |
Final Drive | Chain |
Front Wheel | WM2 x 19 in. |
Rear Wheel | WM2 x 19 in. |
Front Tire | 3.25 x 19 in. Dunlop Gold Seal |
Rear Tire | 3.5 x 19 in. Dunlop Gold Seal |
Front Suspension | Hydraulic fork |
Rear Suspension | Swinging arm fork with shocks |
Front Brake | 8 in., drum |
Rear Brake | 7 in., drum |
Wet Weight | 175 kg / 385 lbs |
Fuel Capacity | 19 L / 5 US gal |
Top Speed | 110 km/h / 70 mph |
Colours | Green/chrome plated tank and black frame /Maroon |
Source | Wikipedia |