The Sunbeam Model 90 motorcycle was produced from 1928-33 and features a single cylinder, four stroke, SOHV engine with a capacity of 493 cc. The compression ratio is 7.0:1, but there are optional ratios of 7.5 and 9.0:1. The bike uses a kick start and has a three-speed transmission with a handshift mechanism. The final drive is via chain, and it features steel laced wire spoke wheels with Dunlop tires. The frame is a single cradle made of steel, and it has Druid-pattern, girder forks on the front suspension and a spring-loaded saddle on the rigid rear suspension. The bike has drum brakes on both wheels and a fuel capacity of 11.4 liters. Top speed for the Sunbeam Model 90 is 145 km/h or 90 mph, and it weighs 143 kg or 315 lbs. The bike was also available in a racing option, weighing 141.5 or 312 lbs, and featuring a 2.75 x 27″ tire size. Overall, the Sunbeam Model 90 is a classic motorcycle with impressive performance capabilities for its time.
Technical specifications:
Make Model: Sunbeam Model 90
| Year | 1928 – 33 |
|---|---|
| Engine | Single cylinder, four stroke, SOHV |
| Capacity | 493 cc / 30.1 cu in |
| Bore x Stroke | 80 x 98 mm |
| Compression Ratio | 7.0:1 (Optional 7.5 or 9.0:1) |
| Cooling System | Air cooled |
| Exhaust | Twin |
| Lubrication | Wet sump |
| Starting | Kick |
| Ttansmission | Three-speed with handshift meganism, medium ratio (BT) or close ratio (CT) |
| Final Drive | Chain |
| Gear Ratios | BT: 1st 10.3 / 2nd 6.9 / 3rd 4.6:1 CT: 1st: 8.4 / 2nd 6.2 / 3rd 4.6:1 |
| Frame | Single cradle, steel |
| Front Suspension | Druid-pattern, girder forks |
| Rear Suspension | Rigid, spring loaded saddle |
| Front Brakes | Drum |
| Rear Brakes | Drum |
| Wheels | Steel, laced wire spokes |
| Tyres, Front and Rear | 3.25 x 26″ Dunlop Racing option: 2.75 x 27″ |
| Dimensions | Length: 2083 mm / 82″ Width: 889 mm / 35″ |
| Wheelbase | 1359 mm / 53.5″ |
| Saddle Height | 711 mm / 28″ |
| Dry Weight | 143 kg / 315 lbs Racing: 141.5 / 312 lbd |
| Fuel Capacity | 11.4 L / 2.5 Imp gal / 3.0 US gal |
| Oil Capacity | 2.8 L / 5.0 Imp pt / 6.0 US pt |
| Top Speed | 145 km/h / 90 mph |
