BSA B31350

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Bsa-b31-02.JPG
BSA B31350
Manufacturer
BSA
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


It could reach a top speed of 110 km/h / 70 mph.

Engine[edit]

The engine was a Air cooled cooled Four stroke, single cylinder, Overhead valve. The engine featured a 6.5:1 compression ratio.

Drive[edit]

Power was moderated via the Multi-plate.

Chassis[edit]

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[edit]

BSA B31350 BSA B31350 BSA B31350

Overview[edit]

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 The model continued in production until 1959, by which time the traditional Lucas magdyno had been replaced by an alternator and coil ignition.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
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