| MODEL | TRIUMPH SPEED TWIN 500 1947 - 1958 |
| Year | 1947 - 1958 |
| Engine Type | Four stroke, parallel twin, OHV |
| Displacement / Capacity | 498 cc / 30.4 cu in |
| Bore X Stroke | 63 x 80 mm |
| Compression Ratio | 7.2:1 |
| Cooling System | Air cooled |
| Max Power | 20.9 kW / 28 hp @ 6000 rpm |
| Max Torque | — |
| Ignition | 6 V magnetic flywheel |
| Induction | Single Amal carburettor 15/16 in |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 4 Speed, constant mesh |
| Clutch | Wet, 6 plate |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Single tube frame |
| Front Suspension | Hydraulic telescopic fork |
| Rear Suspension | Sprung hub 1947-1954, swingarm with two shock absorbers after 1954 |
| Front Brakes | Drum, 7 in SLS |
| Rear Brakes | Drum, 7 in SLS |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | 749 mm / 29.5 in |
| Wheelbase | 1372 mm / 54 in |
| Ground Clearance | 152 mm / 6.0 in |
| Dry Weight | 182 kg / 401 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.25 - 19 Dunlop Universal |
| Rear Tyre | 3.50 - 19 Dunlop Universal |
| FUEL SYSTEM | |
| Fuel Capacity | 18 Litres / 4.8 US gal |
| Fuel Consumption | — |
| Top Speed | — |
The post-war Speed Twin 500 gained a telescopic front fork and, in the early years, an optional sprung-hub rear end, moving to a conventional swingarm after 1954. Wikipedia adds that the 1949 nacelle headlamp and instrument housing arrived in this period and that a Lucas alternator replaced the magneto and generator in 1953. It stayed the smooth, light and handsome 500 twin that anchored Triumph's range.
