| MODEL | TRIUMPH SPEED TWIN 500 1938 - 1946 |
| Year | 1938 - 1946 |
| Engine Type | Four stroke, parallel twin, OHV |
| Displacement / Capacity | 498 cc / 30.4 cu in |
| Bore X Stroke | 63 x 80 mm |
| Compression Ratio | 7.1:1 |
| Cooling System | Air cooled |
| Max Power | 20.9 kW / 28 hp @ 6000 rpm |
| Max Torque | — |
| Ignition | 6 V magnetic flywheel |
| Induction | Single Amal carburettor |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 4 Speed |
| Clutch | Wet, 6 plate |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Single tube frame |
| Front Suspension | Rigid fork with leaf spring |
| Rear Suspension | Rigid, spring-loaded saddle |
| Front Brakes | Drum |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | 182 kg / 401 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.25 - 19 |
| Rear Tyre | 3.50 - 19 |
| FUEL SYSTEM | |
| Fuel Capacity | 18 Litres / 4.8 US gal |
| Fuel Consumption | — |
| Top Speed | — |
The pre-war and early-war Speed Twin 500 kept the rigid frame and the original 63 x 80 mm vertical twin that Edward Turner introduced in 1937. Smooth, stylish and light, it turned Triumph around financially and led many riders from singles to twins. Telescopic forks and a sprung hub were added only in the post-war years.
