A Motorcycle Story – Triumph Bonneville T120


The Triumph Bonneville is an icon of the motorcycle world. The name comes from – of all places – the United States. The Bonneville Salt Flats in Utah was where Triumph and virtually every other manufacturer in the world would travel to in order to do top speed runs and attempt to set world speed records.

From such a beginning and with a name like “Bonneville”, Triumph engineered the machine to be a high-performance motorcycle and the public understood that very well. As the 1959 T120 Bonneville was based on the 650c.c. twin which powered the Tiger 110, it also inherited the Tiger’s optional twin 1 3/16 inch Amal ‘monobloc’ carburetors and high-performance intake cam as standard equipment.

Even the early model T120 was capable of a sustained 115 Mph – an incredible speed for the time. Other innovations to the machine included a unit construction model update, higher spec forks, and the ‘oil in frame’ model in 1971. Many other small improvements were made during its run. Triumph also produced several up-rated versions of the Bonneville, like the T120R for the US market and the T120RV which had a five-speed transmission.

From about 1972, Triumph upped the ante by producing the T140 Bonneville. It increased the engine size to near 750c.c. The first models actually had 724c.c, but they were eventually bored out to 744c.c. The early models of the T140 maintained the T120 drum brakes and basic configuration, including the kick-starter. However, disc brakes were eventually added to the updated models and became dual-disc brakes on the 1982 model. During that time, Triumph also switched the gear-change lever from right to left (to comply with American regulations), added a rear disc brake and put an electric starter on the Bonnie in 1980. Production at the Meriden factory ceased in 1983, but the Bonneville line was continued. John Bloor now owned the marque and he licensed a small shop in Devon to produce T140 Bonnevilles from 1985 until 1988 – they were known as ‘Devon Bonnevilles’.

After Bloor opened the new plant in Hinckley, the first Bonneville to roll off the assembly lines was the 2001 Bonneville 790. It was equipped with a 790c.c. parallel-twin which produced a healthy 62hp and 44ft/lb of torque. The company had decided to have this machine look very much like the classic Bonnies of old, and they succeeded. It had many modern upgrades, such as twin overhead cams versus the pushrods of the earlier models. It did maintain its air-cooled nature and only had an oil-cooler to ensure consistent running temperatures.

In 2005, the new 865c.c. engine was put in place of the 790c.c. original and it was known as the Bonneville T-100. This moved the Bonneville up to 67hp and 51ft/lb of torque. For 2008, fuel injection was added due to increasing emission regulations, and false carburetors were used in 2009 to make it look as if it were not so equipped. The Bonneville SE was made available in 2009 and celebrates 50 years of the Triumph Bonneville; they added several styling features, cast wheels, upswept exhaust silencers and a lower, narrower seat.


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