Triumph T120 Bonneville (1970-71)

The Triumph Bonneville 650 T120 was a motorcycle produced between 1970 and 1971. It was powered by a four-stroke, parallel twin, OHV engine, with a capacity of 649 cc or 39.6 cu in and had a compression ratio of 9.0:1. The cooling system was air-cooled and had 2 x 30 mm Amal concentric carburetors for induction, with battery-coil ignition and kick starting. The lighting system was a 12V alternator, and the oil system had a double plunger pump with dry sump and a capacity of 3.4 L or 7.2 US pt or 6 Imp pt. It had a multi-disc wet clutch, maximum power of 37.3 kW or 50 hp at 7,000 rpm, and a maximum torque of 52.1 Nm or 5.3 kgf-m or 38.5 lb-ft at 6,000 rpm.

The transmission was four-speed, and final drive was via chain. Gear ratios were 4th 4.95 / 3rd 6.14 / 2nd 8.36 / 1st 12.08. The front suspension was telescopic forks, while the rear suspension had a swinging arm with dual shocks. The brakes were drum, both front and rear. The front tyre was 3.25 -19, while the rear tyre was 4.00 -18. It had a fuel capacity of 16L or 4.2 US gal or 3.5 Imp gal, and had a wet weight of 181 kg or 399 lbs.


Technical specifications:

Make Model: Triumph Bonneville 650 T120

Year: 1970 – 71


Engine: Four stroke, parallel twin, OHV
Capacity: 649 cc / 39.6 cu in
Bore x Stroke: 71 x 82 mm
Compression Ratio: 9.0:1
Cooling System: Air cooled
Induction: 2 x 30 mm Amal concentric carburetors
Ignition: Battery, coil
Starting: Kick
Lighting system: 12V alternator
Oil system.: Double plunger pump, dry sump
Oil capacity: 3.4 L / 7.2 US pt / 6 Imp pt
Clutch: Multi-disc, wet
Max Power: 37.3 kW / 50 hp @ 7000 rpm
Max Toque: 52.1 Nm / 5.3 kgf-m / 38.5 lb-ft @ 6000 rpm
Transmission: 4 Speed

Final Drive: Chain
Gear Ratios: 4th 4.95 / 3rd 6.14 / 2nd 8.36 / 1st 12.08
Front Suspension: Telescopic forks
Rear Suspension: Swinging arm, dual shocks
Front Brakes: Drum
Rear Brakes: Drum
Front Tyre: 3.25 -19
Rear Tyre: 4.00 -18
Fuel Capacity: 16L / 4.2 US gal / 3.5 Imp gal
Wet Weight: 181 kg / 399 lbs

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