Triumph Speed Twin (1947-58)

The Triumph Speed Twin 500 was produced from 1947 to 1958 and had a four-stroke, parallel twin, OHV engine with a capacity of 498 cc. Its bore and stroke were 63 x 80 mm and had a compression ratio of 7.2:1. The motorcycle was air-cooled, and its fuel was provided by a single Amal carburetor 15/16″ and ignited by a 6V magnetic flywheel. It had a kick-starting mechanism and could produce a maximum power of 20.9 kW / 28 hp at 6000 rpm. The engine was paired with a wet, six-plate clutch and a 4-speed, constant mesh transmission that drove the rear wheel through a chain. The bike had a single tube frame and hydraulic telescopic forks for the front suspension. Between 1947 and 1954, it had a sprung hub for the rear suspension and two shock absorbers after 1954. The front and rear brakes were both drum, with a 7-inch SLS. The bike had Dunlop Universal tires for the front and rear, with sizes of 3.25 – 19 and 3.50 – 19, respectively. The wheelbase measured 1372 mm / 54 in, with a saddle height of 749 mm / 29.5 in and ground clearance of 152 mm / 6.0 in. It weighed 182 kg / 401 lbs and had a fuel capacity of 18 L / 4.8 US gal / 4.0 Imp gal.

Technical specifications:

Make Model: Triumph Speed Twin 500

Year: 1947-58
Engine: Four stroke, parallel twin, OHV
Capacity: 498 cc / 30.4 cub in.
Bore x Stroke: 63 x 80 mm
Compression Ratio: 7.2:1
Cooling System: Air cooled
Induction: Single Amal carburetor 15/16″
Ignition: 6 V magnetic flywheel
Starting: Kick
Max Power: 20.9 kW / 28 hp @ 6000 rpm
Clutch: Wet,6 plate
Transmission: 4 Speed, constant mesh
Final Drive: Chain
Frame: Singe tube frame
Front Suspension: Hydraulic telescopic fork
Rear Suspension: 1947-1954 sprung hub, after 1954 Swingarm with two shock absorbers
Front Brakes: Drum, 7 in SLS
Rear Brakes: Drum, 7 in SLS
Front Tyre: 3.25 – 19, Dunlop Universal
Rear Tyre: 3.50 – 19, Dunlop Universal
Wheelbase: 1372 mm / 54 in
Saddle Height: 749 mm / 29.5 in
Ground Clearance: 152 mm / 6.0 in
Dry Weight: 182 kg / 401 lbs
Fuel Capacity: 18 L / 4.8 US gal / 4.0 Imp gal