Sunbeam Model 90 (1928-33)

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.

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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