Skip to content

Triumph Bonneville T140ES

British to the last. 

1982 : the year of the Falklands’ War; Michael Jackson’s “Thriller;” and the death of John Belushi. And in March, the Meriden Workers’ Cooperative assembled Bill Sarjeant’s Bonneville T140ES .

Triumph produced its first Bonneville in 1958 for the 1959 year. Named for the Thunderbird-engined 650cc “Texas Ceegar” that hit more than 214 mph at those same Salt Flats in 1956, the Bonnie featured a new splayed port cylinder head with twin carburetors, a one-piece crankshaft, and sports camshafts giving around 48 hp. Finished in pearl and tangerine, and with the trademark Triumph headlight nacelle, the Bonneville hit the US market in 1959—but with more of a whimper than a bang. Neither the colour scheme nor the nacelle were popular, and for 1961, more masculine colours and matched speedo and tach appeared. Unit construction, with the engine and transmission cases combined, arrived for 1963.

The Bonneville underwent continuous development and improvement through the sixties, culminating in what many consider the best years—from 1968 to 1970. These bikes had the excellent eight-inch TLS front drum brake, improved engine breathing for better oil-tightness, and improved handling from a stiffer frame.

bonneville t140esWith 1971 came the new oil-in-frame—and a heap of problems: first, the frame was too tall, making it difficult for most riders to touch ground; and second, it was discovered at the start of production that the Bonneville engine wouldn’t fit in the new frame—unless the rocker boxes were removed first! This and other problems caused BSA-Triumph to miss the US sales season, decimating its revenues. A subsequent run on BSA shares precipitated bankruptcy.

Norton-Villiers owner Dennis Poore bought the failed company and its two main factories (BSA Small Heath and Triumph Meriden), naming the new company Norton-Villiers-Triumph (NVT). With appropriate fixes in place (a thinner seat being one) the 1972 Bonnie introduced a five-speed transmission based on the racing Quaife design. For 1973, capacity was increased to 744cc with a bore increase from 71mm to 76mm, and a disc front brake replaced the limp 1971-2 TLS drum. And that’s when the wheels almost came off the Bonnie …

In 1973, Poore planned to move all Triumph production to Small Heath and close Meriden. The Meriden workforce demurred, closing the factory gates and locking themselves in. Supported by other trade unions, the workers’ cooperative determined to keep building Bonnevilles, and produced a few bikes from their parts inventory. But no new supplies were forthcoming, and it was surely just a matter of time before the cooperative failed too. 

A change of national government ushered in a Labour administration, which decided the Meriden cooperative could become a bold, new experiment in socialist “enterprise.” Industry Minister Tony Benn persuaded his government to fund the workers’ cooperative. Suppliers were also encouraged to support the “venture,” and Bonnevilles were soon once again rolling out of Meriden.

As well as restarting production in 1974, the newly-formed Meriden Workers’ Cooperative had to design a crossover gear linkage for 1975 to meet US DoT requirements. A rear disc brake arrived in 1976. The 1977 model year saw production of 2,400 limited-edition Silver Jubilee models to essentially the 1976 specification, but 1978 heralded a new cylinder head with parallel intake ports and Mk2 Amal carburetors. Electronic ignition arrived in 1979, and the same year saw the T140D Bonneville Special with Lester cast alloy wheels and siamesed exhaust.

Big news for 1980 was—finally—an electric starter, fitted at the rear of the timing chest where the magneto had been on the 1959 Bonnie. The new models were the Bonneville T140ES, T140EX Executive (with full luggage) and the T140LE Royal Wedding of 1981, celebrating the marriage of Charles and Diana. Shown in 1982 was a new eight-valve cylinder head, subsequently fitted to the 1983 TSX. Also in 1983, the TSS appeared with a rubber-mounted engine. Along the way, Bing CV carburetors replaced Amals.bonneville t140es

The cooperative actually struggled on until the last Meriden Bonnie was built in 1984. By that time Margaret Thatcher was prime minister and there was emphatically no more government money. In that year, a young property developer named John Bloor bought the Meriden site from the insolvent cooperative and flattened the factory to build a housing subdivision. At the same time, he acquired rights to the Triumph brand, and licenced Les Harris’s Racing Spares Company in Devon to continue building Bonnevilles until 1988. The first Bloor-licenced Harris Triumph Bonnevilles arrived in 1985 with Marzocchi forks, Brembo brakes and Bosch electrics.

But Bloor had other plans for the Triumph name. Work on the new Triumph factory in Hinckley, Leicestershire started in the mid-1980s, and the new Triumph range of liquid-cooled multi-cylinder bikes was announced in 1990. And, of course, the Triumph story is still being written.

It’s not widely appreciated that new Triumph motorcycles were available in every peacetime model year from 1902 to the present—except for two: 1989 and 1990 

BILL SARJEANT THINKS HIS 1982 Bonneville T140ES may have started life as a Bonneville Executive with factory fairing and full hard luggage. He’s tracked down another 1982 Bonnie in BC that is only five numbers away from his own bike, and that’s an Executive for sure. Although there’s no longer any way of telling, it seems likely the two bikes were built at the same time and shipped together. 

The only real issue Bill has had with his Bonneville T140ES has been setting up the carburetors, which he plans to send to “Doctor Bing,” at the Bing Carburetor Agency in Council Grove, Kansas (  

Or perhaps it was simply that this most British of British bikes just rejected them…

1982 Triumph Bonneville t140ES

by Robert Smith Canadian Biker


Keep independent motorcycle journalism alive! If you found this article interesting or useful, please consider sharing.