| MODEL | SUNBEAM MODEL 90 1928 - 1933 |
| Year | 1928 - 1933 |
| Engine Type | Single cylinder, four-stroke, OHV, twin exhaust |
| Displacement / Capacity | 493 cc / 30.1 cu in |
| Bore X Stroke | 80 x 98 mm |
| Compression Ratio | 7.0:1 (7.5 or 9.0:1 optional) |
| Cooling System | Air cooled |
| Max Power | — |
| Max Torque | — |
| Ignition | — |
| Induction | — |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | Wet sump |
| Gear Box | 3-speed, hand change (medium or close ratio) |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Single cradle, steel |
| Front Suspension | Druid girder forks |
| Rear Suspension | Rigid, spring-loaded saddle |
| Front Brakes | Drum |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | 2083 mm / 82 in |
| Overall Width | 889 mm / 35 in |
| Overall Height | — |
| Seat Height | 711 mm / 28 in |
| Wheelbase | 1359 mm / 53.5 in |
| Ground Clearance | — |
| Dry Weight | 143 kg / 315 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.25 x 26 in |
| Rear Tyre | 3.25 x 26 in |
| FUEL SYSTEM | |
| Fuel Capacity | 11.4 Litres / 3.0 US gal |
| Fuel Consumption | — |
| Top Speed | 145 km/h / 90 mph |
The sporting 493 cc overhead-valve single, with a polished connecting rod, hairpin valve springs and Weslake-advised ports, built to be raced and ridden hard. It won the 1929 Isle of Man Senior TT with Charlie Dodson and took Senior honours at Monza. It was replaced by the Model 95 after 1933.
