Triumph T120 Bonneville (1966-67)

The Triumph T120R Bonneville 650 was a motorcycle model produced from 1966 to 1967. Its engine was a four-stroke, parallel twin, OHV with a capacity of 649cc or 39.6 cubic inches. It had 2 Amal 1-1/6″ carburetors, a Lucas MA6 alternator with 2 coils, and a kickstart. The max power output was 34 kW or 46 hp at 6500 RPM, and it had a wet, multiplate clutch and a four-speed constant mesh transmission with a chain final drive. The frame featured a single front downtube with a second bracing member running under the tank and a steering angle of 65°. The front suspension was telescopic forks with hydraulic damping, and the rear suspension was a swingarm with twin Girling dampers. Both front and rear brakes were SLS drum brakes, with the front being 8″ and the rear being 7″. The motorcycle had Dunlop Universal tires, with the front being 3.25 x 19 and the rear being 4.00 x 18. Its dimensions were length 2020 mm or 85.5 in, width 720 mm or 28.5 in, wheelbase 1403 mm or 55.2 in, seat height 775 mm or 30.5 in, ground clearance 127 mm or 5.0 in, and dry weight 165 kg or 363 lbs. The fuel capacity varied by region, with the US having 13.6 L or 3.6 US gallons, and the UK and other export markets having 18 L or 4.8 US gallons.


Technical specifications:

Make Model: Triumph T120R Bonneville 650

Year: 1966 – 67


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 19, Dunlop Universal
Rear Tyre: 4.00 x 18, Dunlop Universal
Dimensions: Length 2020 mm / 85.5 in Width 720 mm / 28.5 in
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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