Icons #12 Triumph Bonneville

Published: 14 March 2024

The Salt-flat record breaker that spawned the most famous name in British biking history

THE WORLD’S GREATEST BIKES

By Saffron Wilson REPORTER

One of the most recognisable and evocative names in motorcycling, Triumph’s Bonneville has endured the test of time. In the 66 years since it was first launched, the Bonneville has smouldered on through the collapse of the British bike industry only to burn bright again in its revival. During its time, the model has spawned numerous iterations, but there’s been none so important as the original 1959 T120.

With a name like Bonneville, it comes as no surprise to learn that the model’s conception was inspired by pure speed. Following Texan racer Johnny Allen’s success on the famous Utah salt flats in 1956, where he and a Triumph-engined streamliner smashed the world land speed record at 214.4mph, Triumph decided to release a model that capitalised on the achievement – and so the Bonneville was born.

Introduced under the reign of Triumph’s chief designer, Edward Turner, the new model built on the 649cc parallel-twin foundation of the T110 Tiger. Dubbed the T120 Bonneville (the number referencing its claimed top speed) it featured a twin carb instead of a single one, a splayed-port cylinder head, high-lift cams, bigger valves, and higher compression pistons.

Underpinned by a forged single-piece crankshaft and an uprated flywheel, the Bonnie promised a heady 46bhp at 6500rpm – at the time a class-leading figure and the most powerful Triumph yet.

Stealing the limelight at the 1958 Earls Court Bike Show, the Bonnie went on sale for the 1959 model year – but surprisingly, it wasn’t an immediate success. Its arrival coincided with that of the Mini, which brought affordable motoring to the masses and caused bike sales to slump. Coupled with teething troubles, such as heavy vibration, breaking flywheel bolts and bent valves (stronger valve springs were introduced almost immediately) it wasn’t the smoothest of births.

But in the years that followed, refinements and improvements helped the Bonneville overcome these issues to cement its place in history. The once unpopular pearl-grey and tangerine paint (which is now the most rare and sought after) was replaced by the iconic blue and white, the mudguards were cut down and there were improvements to the electrics, carbs and frame. In 1963, a unit construction engine (where the engine and gearbox share a single casing) was adopted, along with new forks and frame improvements. With development throughout the 1960s and the production of the T120C and TT racers, in 1967 the original Bonneville enjoyed its most successful year to date, with 28,000 motorcycles sold in the US alone. That was also the year Evel Knievel chose a T120 for his Caesar’s Palace jump, and John Hartle took the win in the Production TT.

But the bubble was about to burst thanks to the arrival of the Japanese – namely Honda and their 1969 CB750. Although Triumph fought back with the 750cc T140, the downward trend continued due to Honda’s speed and reliability.

In 1972 BSA-Triumph merged into Norton Villiers Triumph before eventually becoming a workers co-operative at the Meriden factory. Production staggered on, but in 1983 the co-operative went into liquidation. Businessman John Bloor bought rights, and in 1984 the factory was demolished to make way for a housing estate. Bonneville Close, Daytona Drive and a roadside commemorative memorial stone now serve as clues to the site’s past.

The factory was no more, but the Bonneville was not dead, with the T140 continuing under license from 1985 to 1988. Then in 2001, Hinckley Triumph resurrected the name with a 790cc parallel-twin, bringing the Bonnie to a whole new generation.

RIVAL: 1969 HONDA CB750

Fresh from the stand at the 1968 Tokyo Show, Britain got its first glimpse of Honda’s new CB750s at the Brighton Motorcycle Show on April 5, 1969, when two prototypes were unveiled. It was a bike that would change motorcycling forever. The first mass production four-cylinder motorcycle boasted a disc brake and electric start. Dubbed as the first ‘superbike’ by many, the improved reliability, speed, and cheaper price tag started an era of Japanese dominance in the motorcycle market and suppressed the last lingering flames of the British industry. The prototype, labelled ‘the Brighton bike’, was sold at the National Motorcycle Museum in 2021 for a record £161,000.

THE BIG MOMENT

‘Johnny recorded 214.4mph’

When 26-year-old Johnny Allen breathed in the atmosphere at the Bonneville Salt Flats on September 6, 1956, he didn’t know he was about to make history. Riding a two-wheeled streamliner built by his mates and housing a Triumph Thunderbird 650 motor with no supercharger, it was a surprise when it smashed the 211mph record set by a factory NSU just a month before.

Allen had been racing since he was 16, and he was fast, claiming 38 race victories in 1949 alone. But after a bad crash in California, he went home to Texas to recuperate.

While there, he met Pete Dalio, a member of a crew planning to break the land speed record. They had hit 165mph with a stock motor, and thought they could push it further, so asked Allen to ride the bike, later known as the Texas Cee-gar.

Allen said yes. They took the bike to Bonneville and he reached 173mph on the first ride, only slowing as the wind lifted the goggles from his face. The second run scored a recorded 191mph.

But their record attempts weren’t over. The bike was fitted with a new one-piece crank, and they lowered the compression ratio (8.5:1) to enable the team to add more nitromethane to the fuel mix.

After two runs, the bike’s average speed was clocked at an astronoimic 214.4mph – a new world record – and two years later, Triumph launched the Bonneville T120 to celebrate the momentous achievement.