BSA A65R (1964-72)

The BSA A65R (Thunderbolt) motorcycle was produced from 1964 to 1972, and was marketed in Europe as the Lightning and in the US as the A65T/R. The bike features a four-stroke, parallel-twin cylinder engine with a capacity of 654 cc and a compression ratio of 9.0:1. It has a 2-into-1 exhaust system and is equipped with a twin coil ignition and Champion N4 spark plugs.

The bike uses a dry sump lubrication system with SAE 20W/50 oil and has a 4-speed transmission with a multi-plate clutch and built-in cush drive. The bike’s frame is made of steel tubing and features telescopic forks with coil springs, while the rear suspension is coil spring/hydraulically damped. The brakes are drums, with a front diameter of 20.32 cm and a rear diameter of 17.78 cm. The bike has steel wire-spoked wheels with front and rear rims of WM2-18 and front and rear tires of 3.25 x 18 in. and 3.50 x 18 in., respectively. The bike’s dimensions are 2060 mm x 711 mm x 1010 mm (L x W x H), with a wheelbase of 1370 mm, ground clearance of 178 mm, and wet weight of 177 kg. The bike has a fuel capacity of 18 L in Europe and 9 L in the US, and an average fuel consumption of 4.7 L/100 km. The bike can reach a top speed of 174 km/h or 108 mph.

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Technical specifications:

Make Model: BSA A65 Thunderbolt

Model: BSA A65R and Lightning (European market) BSA A65T/R (US market)

Year: 1964 – 72

Engine: Four stroke, parallel twin cylinder, OHV

Capacity: 654 cc / 39.9 cub in.

Bore x Stroke: 75 x 74 mm

Carburetors: Amal monobloc 389/67

Cooling System: Air cooled

Compression Ratio: 9.0:1

Lubrication: Dry sump

Engine Oil: SAE 20W/50

Oil Capacity: 3 L / 5 pints / 0.79 US gal

Exhaust: 2-into-1

Ignition: Twin coil

Spark Plug: Champion N4

Battery: 2 x 12V, 10 a.h., Lucas RM19

Starting: Kick start

Max Power: 35.8 kW / 49 hp @ 7000 rpm

Clutch: Multi-plate with bult-in cush drive

Transmission: 4 Speed

Final Drive: Chain

Gear Ratio: 1st 11.49 / 2nd 7.32 / 3rd 5.24 / 4th 4.58:1

Frame: Steel tubing, cradle

Front Suspension: Telescopic forks with coil spring – hydraulically damped

Rear Suspension: Coil spring/hydraulically damped

Front Brakes: 20.32 cm / 8 in., drum

Rear Brakes: 17.78 cm / 7In., drum

Wheels: Steel, wire spokes

Front Rim: WM2-18

Rear Rim: WM2-18

Front Tyre: 3.25 x 18 in., ribbed

Rear Tyre: 3.50 x 18 in., K70

Dimensions: Length: 2060 mm / 81.0 in Width: 711 mm / 28 in Height: 1010 mm / 39.8 in

Wheelbase: 1370 mm / 54.5 in.

Ground Clearance: 178 mm / 7.0 in.

Seat Height: 813 mm / 32 in.

Wet Weight: 177 kg / 397 lbs

Fuel Capacity: Europe:18 L / 4.8 US gal US: 9 L / 2 US gal

Average Consumption: 4.7 L/100 km / 21.3 km/l / 50 mpg

Top Speed: 174 km/h / 108 mph