Triumph Meriden Trident

The staple British bike was the parallel twin, and most were 500 and 650cc. However, the Americans, brought up on Harley-Davidsons, demanded larger capacity twins, and Norton responded in 1962 with the 750cc Atlas. At that stage Norton's archrivals Triumph and BSA, were reluctant to become involved in this capacity quest, but around the same time, two engineers, Bert Hopwood and Doug Hele, left Norton for Triumph/BSA. They instigated the development of a Triumph and BSA 750, and although Triumph's priority was on developing its existing 500 and 650cc twins, eventually Hopwood and Hele managed to persuade a sceptical management to persevere with their 750cc triple.

In the early 1960s a three-cylinder engine was quite unusual, and at its heart was a forged crankshaft, initially reheated and twisted to provide the 120-degree throws. As with the Triumph twins there were two gear-driven camshafts fore and aft of the alloy block, with pushrods in tubes between the cylinders. The 67 x 70 mm bore and stroke provided 740cc, and with a 9.5:1 compression ratio and three individual Amal 27mm carburettors, the power was a claimed 58bhp at 7250 rpm. Triumph included the usual dry sump lubrication, triplex chain primary drive, and a unit four-speed gearbox. The clutch was a new set-up incorporating a single dry plate and diaphragm spring. This engine was housed in a Bonneville-type frame with a single front downtube and bolted on rear subframe. Completing the specification were 19-inch wheels, and drum brakes, although the front double leading shoe brake was stretched to the limit by the weight and speed of the Trident.

When it was initially released, as the Triumph Trident and similar BSA Rocket 3, Triumph aimed them squarely at the US market and went for radical new styling. The ray-gun silencers and a bread-loaf fuel tank may have looked avant-garde, but it failed to win the traditional clientele. In the face of the new Honda 750 Four, the Trident was still very much a conservative motorcycle with strong ties to the past. While the Honda offered more power, and electric start, overhead camshaft, oil tightness, and a five-speed gearbox, the more expensive Trident was burdened with serious quality control problems.

Some salvation for the Trident came in 1970, when American dealers offered a beauty kit. The aim was to make the ugly Trident look more like the traditional twin, and included a 650 Trophy-style fuel tank, and barrel-shaped mufflers. This proved far more popular, and for 1971 all US models featured this new look. The traditional tank continued on the early 1972 US example pictured here, one of the last four-speed Tridents before a five-speed gearbox was incorporated from July 1972. Because of managerial indecision the Trident spent far too long in incubation, and even when it was released the Japanese domination was unassailable.

By Ian Falloon