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.

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