BSA Rocket 3/Triumph Trident

[1] Alongside the Honda CB750, and later the two-stroke Kawasaki triples, it brought a new level of sophistication to street motorcycles, marking the beginning of the superbike era.

[3][4][5] It had a 58 bhp (43 kW), 740-cubic-centimetre (45 cu in) air-cooled OHV unit construction straight-three engine, with four gears and a conventional chassis and suspension.

The Trident has an extra cylinder and, following Triumph practice, its OHV pushrod engine has separate camshafts for the inlet and exhaust valves.

[7] Although the prototype was ready by 1965, the factory delayed for years for a cosmetic redesign which meant that its eventual introduction was overshadowed by the apparently more modern Honda CB750, introduced in 1969.

However, the decision to produce a BSA version with sloping cylinders and employ Ogle Design to give the early Tridents/Rocket 3s their "square tank" added bulk and 40 lb (18 kg) of weight, delaying production by 18 months.

All the three-cylinder engines (and the Rocket 3 motorcycles) were produced at BSA's Small Heath site, but final assembly of the Triumph Trident model was carried out at Meriden in Coventry.

For the 1975 model year, the Trident was updated to the T160 which was given electric starting, front and rear disc brakes, and a left-foot gear change.

They felt the price of $1,800 (£895) was too high, and technical details (like vertically split crankcases and a pushrod OHV valve train were too conventional.

The bike was then sent to the UK, where it received a lukewarm reception from chief designer Bert Hopwood (but a favourable public reaction); the Vetter BSA Rocket 3 became the Triumph X-75 Hurricane.

With forward-sloping cylinders (like the BSA Rocket 3), electric start and a left-hand gearshift, NVT made a final effort to save large-scale production and reduce the gap between the Trident and the Honda CB750.

[12] Changes on the T160: In December 1975 final shipments of 288 and 224 motorcycles were destined for Australia and the US, respectively, but NVT diverted them to fill an order from the Saudi Arabian police force.

In 1982, European dealers imported about 180 low-mileage Tridents from Saudi Arabia; the poorly maintained, sand-encrusted machines were restored and sold as standard T160s.

An inside view is that Hele's efforts were a waste of resources that, with NVT's precarious finances, should have been directed to marketing the 900 cc triple Thunderbird III.

[16] Doug Hele continued to develop the engine, and in 1971 joined frame expert Rob North to produce the Formula 750 racing machines.

[19] John Cooper rode a BSA Rocket 3 to an upset victory over 500 cc world champion Giacomo Agostini in the 1971 Race of the Year at Mallory Park.

[22] Bert Hopwood recommended a production version of the racing triple, producing 84 bhp (63 kW) at 8,250 rpm, but his suggestion was not adopted.

[23] Financial and management problems at BSA and the disintegration of the British motorcycle industry during the early 1970s led to a government-sponsored merger, "NVT", in July 1973 with Norton.

Blue-and-white motorcycle, parked on grass
Prototype Triumph Trident P1, which was on display at the London Motorcycle Museum
Red motorcycle
BSA Rocket 3, restyled for 1971
Orange motorcycle in museum
Triumph X-75 Hurricane
Red-and-white motorcycle, parked on fallen leaves
1975 Trident T160 with electric starting, front and rear disc brakes and left-foot gear change
Green-and-white racing motorcycle in museum
Rob North framed BSA Rocket 3 F750 class at the Sammy Miller Museum