BSA B31

Source-listed reference profile. Prices, fees and availability depend on the market, programme, version and source date.

Detailed specifications and information

Name	BSA B31
Country
Introduced
Region
City
Source	Wikidata
Manufacturer	BSA motorcycles Source
Operator
Location
Mass
Height
Width
Length
Retrieved At	2026-11-02
Engine	348 cc (21.2 cu in) air-cooled single-cylinder OHV four-stroke Source
Power	17 bhp (13 kW) @ 5,500rpm Source
Brakes	Drums front & rear Source
Transmission	Wet clutch , 4 speed gearbox , chain drive Source
Fuel Tank	3 imp gal (14 L; 3.6 US gal) Source
Suspension	Front: Telescopic forks Source

Prices and specifications may change by market and date.

Section	Label	Value	Source Url
1949 BSA B31	Engine	348 cc (21.2 cu in) air-cooled single-cylinder OHV four-stroke	Source
1949 BSA B31	Power	17 bhp (13 kW) @ 5,500rpm	Source
1949 BSA B31	Fuel delivery	1 in (25 mm) Amal carburettor	Source
1949 BSA B31	Transmission	Wet clutch , 4 speed gearbox , chain drive	Source
1949 BSA B31	Suspension	Front: Telescopic forks	Source
1949 BSA B31	Brakes	Drums front & rear	Source
1949 BSA B31	Tyres	325x19 front & rear	Source
1949 BSA B31	Fuel capacity	3 imp gal (14 L; 3.6 US gal)	Source

Field	Value 1
1949 BSA B31	—
Manufacturer	BSA motorcycles
Parent company	Birmingham Small Arms Company
Production	1945-1959
Assembly	Small Heath , Birmingham , England
Predecessor	BSA B38
Successor	BSA B40
Engine	348 cc (21.2 cu in) air-cooled single-cylinder OHV four-stroke
Bore / stroke	71 mm × 88 mm (2.8 in × 3.5 in)
Compression ratio	6.5:1
Power	17 bhp (13 kW) @ 5,500rpm
Ignition type	Magneto
Fuel delivery	1 in (25 mm) Amal carburettor
Transmission	Wet clutch , 4 speed gearbox , chain drive
Suspension	Front: Telescopic forks
Brakes	Drums front & rear
Tyres	325x19 front & rear
Fuel capacity	3 imp gal (14 L; 3.6 US gal)
Footnotes / references [ 1 ] [ 2 ]	—

Manufacturer	Birmingham Small Arms Company
Last sourced	2026-11-02