Triumph T 120 Bonneville (1960-61)

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The Triumph T120 Bonneville 650 motorcycle was produced from 1960-61. It is a four stroke, parallel twin engine with a capacity of 649 cc / 39.6 cu in. The compression ratio is 8.5:1 and the cooling system is air cooled. The induction uses 2 Amal 1 – 1/6″ carburetors, and the ignition is Lucas magneto. The motorcycle has a kick start, with a maximum power of 34 kW / 46 hp @ 6700 rpm. The clutch is wet and multiplate, while the transmission has four speeds and is constant mesh. The final drive is a chain with 101 links, and the gear ratios are 1st 11.90 / 2nd 8.25 / 3rd 5.81 / 4th 4.88:1. The frame is made of twin steel downtubes, and the front suspension is a telescopic fork with hydraulic damping. The rear suspension is a swingarm with twin Girling dampers. The front and rear brakes are drum brakes with the front being 8″ SLS and the rear being 7″ SLS. The front and rear tires are Dunlop brand with sizes 3.25 x 19 and 4.00 x 18, respectively. The wheelbase measures 1400 mm / 55.25 in, and the seat height is 770 mm / 30.5 in. The ground clearance is 127 mm / 5.0 in, and the dry weight is 183 kg / 403 lbs. The fuel capacity is 13.6 L / 3.6 US gal / 3 Imp gal for US models and 18 L / 4.8 US gal / 4 Imp gal for UK and other export models.

Technical specifications:

Make Model: Triumph T120 Bonneville 650

Year: 1960 – 61


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 magneto
Starting: Kick
Max Power: 34 kW / 46 hp @ 6700 rpm
Clutch: Wet, multiplate
Transmission: 4 Speed, constant mesh
Final Drive: Chain, 101 links
Gear Ratios: 1st 11.90 / 2nd 8.25 / 3rd 5.81 / 4th 4.88:1
Frame: Twin steel downtubes
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
Rear Tyre: 4.00 x 18, Dunlop
Wheelbase: 1400 mm / 55.25 in
Seat Height: 770 mm / 30.5 in
Ground Clearance: 127 mm / 5.0 in
Dry Weight: 183 kg / 403 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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