Sunbeam Model 9 (1924-27)

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.

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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