CarBrandLogos archive · Triumph Motorcycles · 1959

Triumph MotorcyclesBonneville T120

Named for a salt-flat record, built to be the fastest thing on a British road.

Photo: Joachim Köhler · CC BY-SA 3.0

The story

A defining chapter in Triumph Motorcycles history.

Explore the ideas, engineering and context that shaped the Triumph Motorcycles Bonneville T120, then continue into its specifications and place in the marque's lineage.

Origins

In September 1956 Johnny Allen ran a Triumph-engined streamliner across the Bonneville Salt Flats at over 214 mph. The international governing body declined to ratify the run after a dispute over timing equipment, but Triumph had what it needed: a name, and the implication behind it. Two years later, at the Earls Court show, the company put that name on a motorcycle.

T140 · Nimbus227 · Public domain

Design and engineering

The T120 was not a new design. It was the 650 twin from the Tiger 110 fitted with twin Amal carburettors, a hotter camshaft and a higher compression ratio, in a package intended to reach the 120 mph its model number advertised. Early bikes kept the pre-unit engine and the headlamp nacelle that Turner liked; from 1963 the engine and gearbox shared a single set of castings and the frame was stiffened, producing the version most people picture when the name is mentioned.

Triumph Bonneville IMG 2738 · Rama · CC BY-SA 2.0 fr

In production

It earned its reputation on the road and then on the track. In 1969 Malcolm Uphill won the Production TT on a Bonneville and lapped the Isle of Man at over 100 mph — the first production machine to do it — which the marketing department turned into the Bonneville Thruxton. In America the twin dominated desert racing and dirt track, and Steve McQueen's public enthusiasm for Triumphs did the brand no harm at all.

Triumph Bonneville on the street · Peprovira · CC BY-SA 3.0

Legacy

What followed was less happy. The 750 cc T140 arrived in 1973 in the middle of the collapse of the BSA-Triumph group, and the Meriden factory was occupied by its workforce, who built Bonnevilles as a workers' co-operative until 1983. A small operation under licence in Devon kept a version in production from 1985 to 1988. When John Bloor restarted Triumph properly, the Bonneville was the model he brought back, in 2001, with an air-cooled twin styled to look like the 1959 bike — and it has been the commercial backbone of the modern company ever since.

At a glance