BSA A50 Cyclone (1962-70)

The BSA A50 Cyclone/Royal Star was a four-stroke, twin-cylinder motorcycle produced from 1962 to 1970. It had a capacity of 498cc and a compression ratio of 9.0:1. The engine was cooled by air and lubricated by dry sump, with a maximum power output of 24.3 kW / 33 hp. The ignition was via a coil with spark plug Champion N4, and it had a kick start. The motorcycle had a multi-plate clutch and a 4-speed transmission with a chain final drive. It had a tubular pipe frame, double cradle with swingarm, telescopic forks for front suspension and double coil over for rear suspension, drum brakes at both the front and rear, and steel wire spoke wheels. The front and rear tyres were 3.25 x 19 inches (ribbed) and 4.00 x 18 inches (K70), respectively. The motorcycle measured 2100mm (81in) in length, with a height of 1117mm (44in) (western)/ 1028mm (40.5in) (standard), and had a wheelbase of 1391mm (54.8in). With a dry weight of 141kg (311lbs) and wet weight of 177kg (391lbs), its fuel tank had a capacity of 18.2 L / 4.0 Imp gal / 7.57 L / 2 US gal.

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Technical specifications:

Make Model: BSA A50 Cyclone/Royal Star

Year: 1962 – 70

Engine: Four stroke, twin cylinder

Capacity: 498 cc / 30.4 cub in.

Bore x Stroke: 65,5 x 74 mm

Cooling System: Air cooled

Compression Ratio: 9.0:1

Lubrication: Dry sump

Oil Capacity: 3 L / 6.3 US pints

Carburetors: Dual, 1 1/16 in carburetors

Exhaust: Twin, stainless steel

Ignition: Coil

Spark Plug: Champion N4, 0.025 in. gap

Starting: Kick start

Max Power: 24.3 kW / 33 hp @ 5800 rpm

Clutch: Multi-plate

Transmission: 4-Speed

Final Drive: Chain

Frame: Tubular pipe, welded, double cradle with swingarm

Front Suspension: Telescopic forks

Rear Suspension: Double coil over

Front Brakes: Drum, 8 in.

Rear Brakes: Drum, 7 in.

Wheels: Steel, wire spoke

Front Tyre: 3.25 x 19 in., ribbed

Rear Tyre: 4.00 x 18 in. K70

Dimensions: Length: 2100 mm / 81 in. Height: Western: 1117 mm / 44 in. / Standard: 1028 mm / 40.5 in

Wheelbase: 1391 mm / 54.8 in.

Seat Height: 840 mm / 33 in.

Dry Weight: 141 kg / 311 lbs

Wet Weight: 177 kg / 391 lbs (4 gal tank)

Fuel Capacity: 18.2 L / 4.0 Imp gal 7.57 L / 2 US gal