BSA Road Rocket (1954-58)

The BSA Road Rocket is a motorcycle that was manufactured from 1954 to 1958. It had a four-stroke parallel twin-cylinder engine with a capacity of 646 cc, and used an Amal carburetor for fuel delivery. The engine had a 7.2:1 compression ratio and was cooled by air. The motorcycle was equipped with twin stainless steel exhausts and a Lucas magdyno ignition system. The Road Rocket had a multi-plate clutch with built-in cush drive, and a 4-speed transmission. It was driven by a chain and had front and rear drum brakes. The frame was made of welded seamless steel tubing with duplex downtubes and full cradle engine support, and had a bolted-on rear subframe. The front suspension was telescopic forks with coil spring and the rear suspension from 1954 onwards was a swinging arm, with a plunger-type shock and rebound springs. The motorcycle had steel wheels with wire spokes, and its tyres measured 3.25 x 19 in. at the front and 4.00 x 19 in. at the rear. The bike was 2100 mm long, had a wheelbase of 1391 mm, and weighed 190 kg dry. The fuel capacity was 16 L and the average fuel consumption was 5.6 L/100 km. The Road Rocket could reach a top speed of 175 km/h and complete the standing quarter mile in 16 seconds. It was available in all-over gold, and black/chrome colours.

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Technical specifications:

Make Model: BSA Road Rocket

Year: 1954 – 58

Engine: Four stroke parallel twin cylinder, OHV

Capacity: 646 cc / 39.4 cub in.

Bore x Stroke: 70 x 84 mm

Carburetor: Amal

Cooling System: Air cooled

Compression Ratio: 7.2:1

Lubrication: Dry sump

Exhaust: Twin, stainless steel

Ignition: Lucas magdyno

Battery: 6V

Starting: Kick start

Max Power: 30 kW / 40 hp @ 6000 rpm

Clutch: Multi-plate with bult-in cush drive

Transmission: 4 Speed

Final Drive: Chain

Gear Ratio: 1st 11.68 / 2nd 7.96 / 3rd 5.48 / 4th 4.53:1

Frame: Welded seamless steel tubing with duplex downtubes and full cradle engine support, bolted-on rear sub frame

Front Suspension: Telescopic forks with coil spring – hydraulically damped

Rear Suspension: None or Plunger-type, with shock and rebound springs, undamped. From 1954: Swinging arm

Front Brakes: Drum, 8 in.

Rear Brakes: Drum, 7 in.

Wheels: Steel, wire spokes

Front Tyre: 3.25 x 19 in., ribbed

Rear Tyre: 4.00 x 19 in.

Dimensions: Length: 2100 mm / 84.0 in.

Wheelbase: 1391 mm / 54.75 in.

Dry Weight: 190 kg / 418 lbs

Fuel Capacity: 16 L / 4.2 US gal

Average Fuel Consumption: 5.6 L/100 km / 17.9 km/l / 42 US mpg

Top Speed: 175 km/h / 109 mph

Standing Quarter Mile (400 m): 16 sec.

Colours: All over gold, Black/chrome

Source: Wikipedia