The Sunbeam Model 9 motorcycle was produced between 1924 and 1927. It has a single cylinder, OHV engine with a 493 cc / 30.1 cu in capacity, air-cooling and a compression ratio of 6.5:1. The lubrication is dry sump, with an AMAC carburettor and a single exhaust. The ignition is by EIC magneto and it has a push start with a power output of 2.6 kW / 3.5 hp. The transmission is a 3-speed, medium ratio with optional gear ratios of 9.7, 6.5, 4.3:1 or 11.0, 7.4, 4.9:1 for sidecars. The final drive is by chain. The frame is a single front down tube with Druid forks at the front and rigid, spring-loaded saddle at the rear. The brakes are drum, internal expanding with steel, laced wire-spoke wheels with 3.25 x 26″ tyres, optional 3.50 x 26″. The dimensions are; Length: 2083mm / 82.0″, Width: 813mm / 32.0″, Wheelbase: 1372mm / 54.0″ and Saddle height: 711mm / 28.0″. The fuel capacity is 11.4 L / 2.5 Imp gal / 3.0 US gal, with an oil capacity of 2.3 L / 4.0 Imp pt / 4.8 US gal. Source: Marston-Sunbeam / Bonhams.
Technical specifications:
Make Model: Sunbeam Model 9
| Year | 1924 – 27 |
|---|---|
| Engine | Single cylinder, OHV |
| Capacity | 493 cc / 30.1 cu in |
| Bore x Stroke | 80 x 98 mm mm |
| Cooling System | Air cooled |
| Compression Ratio | 6.5:1 |
| Lubrication | Dry sump |
| Induction | AMAC carburettor |
| Exhaust | Single |
| Ignition | EIC Magneto |
| Starting | Push |
| Power | 2.6 kW / 3.50 hp |
| Transmission | 3-Speed, medium ratio |
| Gear Ratios | 1st 10.3 / 2nd 6.9 / 3rd 4.6:1 Optional: 9.7, 6.5 and 4.3:1 or 11.0, 7.4 and 4.9:1 Side car: 11.8, 7.9 and 5.25:1 or 12.6, 8.4 and 5.6:1 |
| Final Drive | Chain |
| Frame | Single front down tube |
| Front Suspension | Druid forks |
| Rear Suspension | Rigid, spring loaded saddle |
| Front Brakes | Drum, internal expanding |
| Rear Brakes | Drum, internal expanding |
| Wheels | Steel, laced wire spokes |
| Tyres, Front and Rear | 3.25 x 26″ (Optional: 3.50 x 26″) |
| Dimensions | Length: 2083 mm / 82.0″ Width: 813 mm / 32.0″ |
| Wheelbase | 1372 mm / 54 in |
| Saddle Height | 711 mm / 28.0″ |
| Saddle Height | 711 mm / 28.0″ |
| Fuel Capacity | 11.4 L / 2.5 Imp gal / 3.0 US gal |
| Oil Capacity | 2.3 L / 4.0 Imp pt / 4.8 US gal |
| Source | Marston-Sunbeam / Bonhams |
