- Engine: 741cc air-cooled 4-stroke triple, 67mm x 70mm bore and stroke, 9.5:1 compression ratio, 58hp @7,250rpm
- Top speed: 117mph (period test)
- Carburetion: Three 26mm Amal Premiers
- Transmission: 5-speed, right foot shift, chain final drive
- Electrics: 12v, aftermarket electronic ignition
“One thing can be said about performance — breathtaking.” Cycle Guide, September 1972
Back in the day, Triumph Tridents were pretty fast. They did well at the drags and performed on the track. Somehow, in the years since production stopped, Triumph Tridents have gotten a reputation as dogs — slow, unresponsive dogs. Scott Dunlavey, the owner of this 1974 T150, builds modern race engines and should know a greyhound from a bulldog. He says Tridents are greyhounds.
Back in the day, Scott rode a Trident back and forth to college. It was fast and reliable, and the only problem he had was the number of times he had to stop for gas on the 227 mile trip — exacerbated by flogging the bike outside of populated areas. “It got 35 miles to the gallon. Triumph geared it low to keep up with Honda 750s.”
Now once again a proud Trident owner, Dunlavey shares his tips for making a Trident run. No special prep is needed — just a good tune-up, unrestrictive mufflers and good air flow to the carburetors. “Tridents like air and gas,” he says.
Poor timing
Scott also points out that the Trident is Exhibit A for just about everything that went wrong with the British motorcycle industry. In the 1960s Triumph was owned by the group that also made BSAs. The people who worked for each brand hated each other’s bikes, which made for some interesting inter-factory clashes. The triple was designed at the Triumph Meriden works by Bert Hopwood, Doug Hele and Jack Wicks in 1963. The prototype, which was ready for production in 1965, looked very much like the good looking Triumph Bonnevilles of the time. Getting it into production would seem to have been a priority, given that management had heard rumors that Honda was building a 750cc motorcycle.
However, the BSA group was run by suits with no motorcycle experience or understanding of the motorcycling public. The suits delayed the introduction of the triple for three years for a cosmetic redesign — by Ogle Designs, a firm whose only prior work had been on automobiles. They also insisted that BSA produce its own version. As a result, the triple came out in 1968, a few weeks before the Honda 750. The technologically advanced Honda snatched public attention away from the British product.
To make matters worse, the Ogle design was not particularly loved by the motorcycle public, and cost the company money that could have been used to develop an electric start or a front disc brake. The Ogle design was particularly badly received in the United States, which was Triumph’s biggest market. To try to salvage sales, Don Brown, BSA’s U.S. branch vice president, commissioned Craig Vetter to redesign the bike, a project which resulted in the X-75 Hurricane, the first factory custom. Although it was unveiled in 1970, production did not start until the 1972 model year, due to internal turmoil at BSA, which was losing money and dragging Triumph down with it. Some 1,200 Hurricanes were built before production stopped due to inability to meet new U.S. noise requirements.
In the middle of 1970, Triumph made a kit available with a teardrop shaped tank, black side covers and conventional mufflers, which reverted the motorcycle to the look of the prototype. Sales improved.
The first Tridents fed power from the 741cc engine via a 5-speed transmission. The engine made 58 horsepower, which was pretty respectable in the late Sixties. The 120-degree crankshaft was carried in aluminum cases. The cylinders and heads were aluminum alloy. Instead of the traditional multiplate clutch, the Trident used a Borg and Beck single plate diaphragm clutch. Cycle World recorded a top speed of 117.03mph in a 1968 road test. It timed the triple at the then obligatory quarter mile drag strip at 13.71 seconds at 98.46mph.
Shootout contender
In 1970, Cycle announced a Superbike Shootout and invited a group of fast heavyweights, including the Trident, to participate. The testers liked the bike. “The big triple went around the course like it was on rails: no snakes, no wobbles, and I could lean it way over. The forks and shocks were perfectly tuned to the rest of the bike … I can understand how Rusty Bradley, Virgil Davenport and Roger Beaumont can consistently win production road races on Tridents.” On the minus side, testers did not like the hard clutch pull and the vibration between 5,000 and 6,000rpm. Both the Trident and the BSA version, the Rocket 3, cost almost as much as the Harley Sportster — the most expensive bike in the test. Then as now, cost was an important element in purchase decisions.
In July 1972, the Trident received a fifth gear for the 1973 model year and a 10-inch front disc brake. The 5-speed Trident was denominated T150V, the V representing the Roman numeral 5. Cycle did another Superbike Shootout in 1973. Testers found the clutch to be much easier on the hands, and braking was no problem. The Trident had the third fastest lap time and, “offered the best combination of cornering ability and low scare factor.” In the acceleration test, “It was the most perfectly-geared motorcycle.” Testers had set an impressive quarter mile time and were trying to get the bike to run 12.5- or 12.6-second quarter miles before second gear shredded. Even so, the Trident came in third place in points in this test, behind the Kawasaki 750 2-stroke and the 900cc Z1.
During this time, Tridents and the BSA sister ship, the Rocket 3, consistently showed up in road racing winner’s circles. In 1971, Dick Mann won Daytona on a Rocket 3, with Gene Romero on a Triumph Trident second and Don Emde third on another Rocket 3. John Cooper, riding a Rocket 3, beat out Giacomo Agostini on a MV Agusta in the 1971 Race of the Year at Mallory Park, England. The best known racing Trident was Slippery Sam, who won every 750cc production races at the Isle of Man TT between 1971 and 1975.
The turmoil and monetary losses continued at BSA. The workers at the Triumph factory in Meriden, England, grew angrier by the day as one bad decision followed another. In July, 1973, control of BSA’s motorcycle-related assets was given by the British government to Dennis Poore, the head of the Manganese Bronze holding company that also controlled Norton, with hopes to save what was left of British motorcycle manufacturing. It soon became clear that Poore only wanted to strip out the remaining assets of BSA and Triumph. In September 1973, the Meriden unions organized a sit in and strike. The strike dragged on for months, while management desperately tried to regain control. In 1974, the strikers released some equipment to be used to build Tridents at the Small Heath factory, and some stockpiled Bonnevilles. Eventually, the government brokered a settlement, loaning the strikers money to buy the Meriden factory. The strikers formed a co-op, and built Bonnevilles at Meriden until 1983.
The strike resolved, BSA started manufacturing Tridents at the former BSA factory near Wolverhampton. By this time, U.S. environmental protection regulations specified emissions control and noise reduction. Other new regulations mandated a left foot shifter. The 1975 Trident was a very good looking bike and sported an electric starter, but suffered badly from a restrictive air cleaner and mufflers that not only choked the engine but also set up a resonant vibration that became annoying after a few miles. To make matters worse, the Trident cost more than the Kawasaki Z1. When the Dennis Poore controlled companies went to Parliament to ask for further loans, the British government threw up its hands, refused to come up with more money, and that was the end of the Trident.

After the Meriden co-op was liquidated in 1983, the rights to the Triumph name and patents were bought by John Bloor, who built a completely new factory nearby Meriden, in Hinkley, and started manufacturing state of the art bikes. The new Triumph factory is doing well, and has recently decided to build an updated Triple with the Trident look.
Going back
Many of the Tridents built in 1974 were shipped to the U.S. One was bought by a person who after owing it for a while brought it to a dealer for repairs. The owner decided he couldn’t afford the repairs and abandoned the bike. For some reason, the dealer never sold it. “I walked past that bike every day for 25 years,” says John Rios, formerly a mechanic at that shop.
Meanwhile, the shop that had the 1974 Trident decided to close down operations and held an auction. Scott Dunlavey was now running a motorcycle dealership in Northern California and collecting classic Triumphs. He decided he wanted this Trident. Eddie Mulder, well known West Coast racer and race promoter, was going to attend the auction and offered to bid on the triple for Scott. When the dust settled, Mulder had the bike and hauled it to Scott’s shop. Scott paid Mulder back and now once again had a Trident.
Scott runs Berkeley Honda Yamaha Tuesday through Saturday, hangs out with his family on Sundays and works on his vintage bikes on Mondays. Even through he is a skilled mechanic, he spent a year’s worth of Mondays getting this Trident running properly. “I called it ‘Triple Trouble.’ The bike was supposed to be running when Eddie got it for me. I tried to go on a test ride. It would start, then die on the side of the road. It took me a year and a lot of calls to Mitch Klempf (klempfsbritishparts.com) to get it going. Mitch is a great resource. There is a huge amount of triple knowledge out there. People who are really into Triumphs love triples.”

One of the trials of maintaining a Trident back in the day was setting three sets of points. Scott eventually ran out of patience. “After quite a bit of time, I gave up and ordered a TriSpark electronic ignition. I spent hours wrestling with the original Amal Concentrics — all three of them — and bought a set of Amal Premiers, the new Amals, which really work well. I put the original mufflers in a box with the points and the old Amals and installed peashooter mufflers from a T140 Bonneville twin. They go right on triples, don’t restrict the engine and sound great.” The original ape hanger handlebars also went into the box, to be replaced with more sporting Western style bars.
After replacing all the rubber and the hydraulic system for the disc brake, tuning the new carburetors and changing the oil, Scott had the T150V ready for the road.

Dunlavey thinks that the reputation Tridents have for being slow may have been derived from the late 1974 version and the 1975 model. “Late 1974 Tridents had a solid air cleaner to meet noise regulations. Early 1974 Tridents had an air cleaner like the one on my bike, that looks like a half umbrella. The half umbrella air cleaner works well. The later one was basically a Band-aid to get the Tridents EPA legal, so they could be sold in the U.S. The mufflers for the later models are also overly restrictive, so replace them with the earlier version or mufflers for a T140 Bonneville.
“Make sure the jetting is correct. If you replace the existing Amals with the new version, Premiers, you will get carburetors with the wrong jets. It took me five hours to yank off the Premiers I had just installed, set them up with the right jets and slides, and reinstall. If you do it, hope that you got it right, because you really don’t want to go through it again.
“Electronic ignition is the biggest thing to happen to Tridents. No more setting three separate sets of points.”
The T150V is kickstart only, but the starting ritual is not too involved. “Tickle the carbs, pull the choke, free the clutch and KICK. It takes a couple of minutes to warm up. Even though it is 100 pounds heavier than a Bonneville, it is a sweetheart around town.”
On the open road at speed, the Trident is very stable and handles well until it gets into really tight mountain roads. “You can feel the extra weight when you flip it left to right in the tight stuff. But when you take it out on a country road and open it up, the howl that they make when they are right on the money — it’s intoxicating.”
Triumph Tridents are a transition bike between classic and modern, with a lot of “if only” about them. Dunlavey thinks that the Trident would have been the bike to save Triumph, if only the 1960s Triumph management had its act together.
“The bike was fast, it was reliable, it was good looking. Triumph could have brought it out in 1965, maybe with the disc front brake. Then when the Honda 750 came out, it wouldn’t have been such a revelation.”
Trident Buyer’s Guide
This guide to the Triumph Trident and BSA Rocket III will tell you everything you need to know about both models. This informative guide will be a great resource, whether you are buying or selling one of these great machines. This guide includes information on pricing, differences between models, details on original or aftermarket features, and more. This title is available at MotorcycleClassics store or by calling 800-880-7567. Item #10834.