Triumph T 120 Bonneville (1963-64)

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The Triumph T120 Bonneville 650 was a motorcycle produced from 1963 to 1964, boasting a four-stroke parallel twin engine with a capacity of 649 cc. It had a compression ratio of 8.5:1 and a maximum power output of 34 kW/46 hp at 6500 rpm. The bike’s ignition system was a Lucas MA6 alternator with two coils, and it started with a kick. The clutch was wet and multiplate, and the transmission was a 4-speed constant mesh. The final drive was a chain with 106 links, and the gear ratios were 1st 11.80, 2nd 8.17, 3rd 6.76, and 4th 5.84:1.

The frame of the T120 Bonneville had a single front downtube and a second bracing member running under the tank, with a steering angle of 65o. The front suspension was telescopic forks with hydraulic damping, and the rear suspension was a swingarm with twin Girling dampers. The front brakes were 8″ SLS drum brakes, and the rear brakes were 7″ SLS drum brakes. The front and rear tyres were Dunlop Universal, with sizes of 3.25 x 18 and 3.50 x 18, respectively.

The bike had a wheelbase of 1403 mm (55.2 in), a seat height of 775 mm (30.5 in), and a ground clearance of 127 mm (5.0 in). Its dry weight was 165 kg (363 lbs), and it had a fuel capacity of 13.6 L (3.6 US gal / 3 Imp gal) for the US market, and 18 L (4.8 US gal / 4 Imp gal) for the UK and other export markets. The Triumph T120 Bonneville 650 was a classic motorcycle with a distinct design and specifications that set it apart from other models of its time.

Technical specifications:

Make Model: Triumph T120 Bonneville 650

Year: 1963 – 64


Engine: Four stroke, parallel twin, OHV
Capacity: 649 cc / 39.6 cu in
Bore x Stroke: 71 x 82 mm
Compression Ratio: 8.5:1
Cooling System: Air cooled
Induction: 2 x Amal 1 – 1/6″ carburetors
Ignition: Lucas MA6 alternator with 2 coils
Starting: Kick
Max Power: 34 kW / 46 hp @ 6500 rpm
Clutch: Wet, multiplate
Transmission: 4 Speed, constant mesh
Final Drive: Chain, 106 links
Gear Ratios: 1st 11.80 / 2nd 8.17 / 3rd 6.76 / 4th 5.84:1
Frame: Single front downtube, second bracing member running under tank
Steering Angle: 65o

Front Suspension: Telescopic forks, hydraulic damping
Rear Suspension: Swingarm, twin Girling dampers
Front Brakes: 8″ SLS drum
Rear Brakes: 7″ SLS drum
Front Tyre: 3.25 x 18, Dunlop Universal
Rear Tyre: 3.50 x 18, Dunlop Universal
Wheelbase: 1403 mm / 55.2 in
Seat Height: 775 mm / 30.5 in
Ground Clearance: 127 mm / 5.0 in
Dry Weight: 165 kg / 363 lbs
Fuel Capacity: US: 13.6 L / 3.6 US gal / 3 Imp gal / UK and other Export: 18 L / 4.8 US gal / 4 Imp gal

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