Rebuilt 1973 Triumph Trident T150V

This late T150V Trident, fully and expertly rebuilt by keeper Peter Hall, finally sells your tester on three-cylinder power.

Words: STEVE WILSON Photographs: GARY CHAPMAN

I never owned a Trident. Back in the day (1970s/early 1980s), if you wanted a Brit roadster that was good for the long roads, motorways included, it was pretty much a Triumph triple or a Norton Commando. For eight years, I favoured the latter, and was not disappointed.

I’d owned a string of Norton twins already, and the Triumph triples had a reputation as intimidatingly and expensively high maintenance. Since then, the late triple expert John South had been persuasive about their virtues, and being a far quicker rider than I, their performance.

John let me out on his ratty X-75 Hurricane factory custom, and I loved its looks and pzazz, though the extended front end and conical hub front drum brake meant that it was really a cruiser, not a roadburner. I tested a T160, another good looker, but while undeniably quick, found the really minimal clutch clearance and uncomfortably thin seat contributed to an impression of a not-quite-practical roadster.

The One For Me 

These subjective judgements would rightly be contested by fans of the model. But even they would admit to its sometimes intimidatingly high oil consumption, and often shockingly low mpg figures, especially if the performance was used to the full. Today solutions have been found for many of the triples’ problems, but they can be pretty expensive. And not even the fans can deny that despite its racing successes and undoubted power, the triples had endured a troubled history.

This had its roots in the complex manufacturing process for the engine, which took place at BSA’s Small Heath works. The complexity had been doubled by the decision to make it in both BSA and Triumph versions, the upright-engine Trident and the forward-slanted Rocket 3. The net result was that the BSA Group was never able to make enough of them to recover the considerable cost of their development and manufacture, despite their having been envisaged as a stopgap model.

An American executive had pointed out to the Group’s Chairman that at a time when the Honda’s new 750-4 were selling up to 30,000 annually in the USA, BSA/Triumph would need to move at least 10,000 of the more expensive triples to make a profit. But the best they ever managed, in the 1972 model year, was 5491 of both the T150 and the Rocket 3 in its final year.

It had been a Mk.II A75 Rocket 3, restored and fitted with an electric start by this T150V’s keeper, retired mechanic Peter Hall, which had been the last triple I had sampled (TCM, October 2024). It had not really been a fair test, as we were mostly confined to narrow country lanes where the BSA’s performance could not be fully experienced, and its claimed 450lb dry weight had been all too evident.

So for Peter’s T150V Trident, manufactured in October 1973 just as the Meriden lock-in was beginning, so only sold in October 1974, we chose a venue, the Berkshire Downs by the Ridgeway, where a riders’ road down towards Hungerford would give the Triumph a better chance to shine. And posed for the photographer against a vista of the Vale of the White Horse, one virtue jumped straight out – for this observer, the late T150 was a really good-looking machine. Which arguably had not always been the case for Tridents.

Beauty Kit 

The tale is well known of how the BSA Group turned over the triples’ styling to the Ogle agency, whose previous form had included the Reliant Robin. Launched in Sept 1968, the resulting strikingly different look, with the slab-sided tank, finished in wishy-washy Aquamarine blue for the Triumph, and the big ‘Raygun’ silencers with three tiny tail-pipes, was, at the least, different enough to deter many an ever-conservative British motorcyclist. It looked heavy, and was, with the early T150s weighing in kerbside at 499lbs, when a 750cc Commando Fastback was 415lbs dry.

But in North America, where by then some 80% of the Group’s machines were sold, it was way worse. As legendary Texas Triumph dealer Jack Wilson of Big D Motorcycles put it, “We couldn’t give those early Tridents away, they were so ugly.” By 1969, the big Detroit dealer Bob Lepan had 100 Tridents warehoused, many of them unsold machines from the West Coast.

Detroit was Style Central for automobiles and motorcycles, so Lepan duly stripped the T150s’ 4.25 Imperial gallon ‘breadbox’ tanks, the Raygun silencers and the awkward-looking side-panels enclosing the big single air filter. He substituted custom-painted TR6 or T120-type 2.75 Imperial gallon ‘teardrop’ gas tanks, with Triumph twin-style badges and knee-grips, barrel silencers, and moulded side-panels no longer covering the air filter. By April 1970 the Meriden factory were supplying versions of these and other changes in ‘beauty kit’ form for the US, and sales took off.

It was not all positive. The smaller, waisted tanks let in more rainwater to the bank of carburettors, via the carb needles’ rubber seals. With mpg sometimes in the mid- 20s, they also restricted range. The barrel, and later, conical, silencers did not release power quite as efficiently as the Rayguns, where Ogle had heeded Doug Hele’s brief to feature large enclosed volume, suitable for containing reverse-flow internals; Hele would retain the Rayguns on works production racers. Nor did they release the unique chilling howl on full chat. But overall, going with what was essentially the twins’ look proved a winner commercially and, to me, stylistically.

It was enhanced for 1971 by the adoption of the new oil-in-frame twins’ ungaitered Ceriani-style front forks. The downside was that they carried the conical hub front brake. This replaced the previous excellent-as-far-as-it-went BSA/Triumph eight inch tls drum, and even that had been barely adequate for a 125mph-plus, 58bhp machine. The megaphone silencers were also fitted then. 

The 1972 season brought the 10-inch disc front brake; and after initial serious glitches, saw the phasing in of the five-speed gearbox, welcome in view of the triples’ relative lack of bottom end grunt, and the consequent need to rev to get the best from them. When you did so, as US Cycle magazine put it in their 1970 ‘Big 7’ Superbike Shoot-out (the Trident came second overall, behind the Commando), on the drag-strip a stock T150 achieved a then very creditable 12.78 second standing quarter, after revving to 6000 and “coming out of the hole like a freight train.”

The Works 

Peter Hall acquired his 1974-registered T150V early in 2025 from a classic car dealer. It was complete and running, but without documentation and very tatty; the history had been lost, but it was not a re-import from the USA.

From the state of the oil when the sump was drained, Peter wisely decided not to run the engine any more before undertaking a full strip-down. Since the frame needed repainting, that became a full chassis rebuild too. The frame went off for powder-coating, both mudguards had to be replaced (with originals from a donor bike) as many extra holes had been drilled in them, and the chrome was poor. Many small components needed renewing, and they all had to be polished or painted. The frame’s headstock bearings were changed.

With the engine removed and stripped, new crank shells were sourced and the crank cleaned out. New piston rings and valve guides were fitted, while the clapped-out clutch was replaced wholesale. Sticky sludge at the bottom of the oil tank meant that every oil line and oilway, including those in the engine plus the oil cooler, had to be cleaned out, and a new oil filter fitted. Happily, no oil-related damage was discovered in the engine, but if it had been run, it wouldn’t have taken long.

Electrically, Boyer electronic ignition, three new 6v coils, a new headlamp and Lucas indicator set were all fitted. Otherwise, one new wheel rim with spoke set was assembled, a new replacement brake master cylinder fitted, along with two Avon RoadRunner tyres. One new silencer, a new kickstart, and replacement rear units, completed the Parts roster. Aiming for state-it-left-the-factory-in condition, Peter doesn’t do things by halves.

Having rebuilt the Rocket 3, Peter can now compare the two. I’d heard rumours that the BSA’s duplex downtube chassis gave an edge in handling over the T150. But Peter dismisses that, saying “The handling is much the same, little to choose between them, both very good. The engines are almost equal, but while the Rocket 3 is super smooth, the Trident seems nippier. The disc front brake on the Triumph is far better than the ‘comical ‘ub’ on the BSA.

“The wide export bars on the Rocket 3 Mk.II are lovely, but the stock bars on the UK Trident were too narrow for my liking, so I’ve now fitted wider 30 inch ones, which I find a big improvement. The five-speed gearbox on the Trident is good, slightly better than the BSA’s four-speed. As to looks, the Trident with its tear-drop tank etc looks very similar to the later o.i.f. Bonnevilles, but the Mk.II Rocket 3, aimed at America with its white frame, chromed two and three-quarter gallon tank and candy colours, has the bling factor while also being more comfortable to ride. So, my view is, it’s the Trident for high-speed thrills and weekend blasts, and the Rocket 3 Mk.II for powerful touring with eye-catching style. They come out even.”

Right Bike, Right Day

A warm Autumn sun was shining over the Vale that test day. I was glad of it, as I’ll admit to some apprehension about riding this fast, heavy classic. Peter Hall started it third kick, and a deep satisfying roar filled the mild air. He then adjusted the tickover to slightly faster, so that I’d be less likely to stall it at rest. The clutch was a fairly stiff pull, but I’d been expecting that, and letting it out, the travel before it engaged was quite short, but not like the T160. And we were off.

The road rose a little, then reached and crossed the Ridgeway path. The gearchange was a bit stiff but not notchy, as I gave it some throttle and changed up into third, the bike proving comfortable at 30 in that gear, not fussing after revs; the gearing had been satisfactorily lowered for 1972, though this had done nothing for petrol consumption…

The road straightened as I was getting a feel for the plot, and it was good. The riding position and seat were comfortable, and there was little or no vibration. The T150V felt solid on the road, with steering a little heavy due to the weight being well forward, but not sluggish. A sharpish left bend came up and the Trident took it calmly, the Avons’ grip as usual excellent, and the engine accelerating away smoothly.

At 50, we hit a straight stretch before the downhill curves, and I throttled on. Wha-hey! This Triumph was eager! Though the acceleration was strangely smooth rather than arm-wrenching, it was solidly powerful. Changing up and keeping it coming, my stomach lurched a little as at 65, near 4000 rpm, the engine let me know that we were just in the foothills, that there was seriously more to come if you wanted it. Because the handling and braking (excellent front disc) were so good, it wasn’t that oo-err barely-in-control rush you get cracking on with, say, a Norton P11, but more like a calm but quietly urgent voice offering you something that might take you outside your comfort zone, but only if you wanted to.

I was liking this. Downhill curves at 60, another straight, a series of tightening bends, getting to know the Trident a little more. It was not a bike that you could chuck about lightly, the weight and some ground clearance limitations discouraged that. But it was calm, solid, unfussy but always lively, and through the much-appreciated five gears, as quick (or not) as you wanted.

When after several miles I pulled into a layby, the raised tickover meant that I couldn’t get it into neutral (back at base, Peter would adjust it to the former setting and then I could). After holding it on the clutch ticking over steadily for a minute, I made a U-turn in one go over the two-lane and rode off again, increasingly confident and exhilarated.

The engine, rebuilt less than 1000 miles before, felt a little tight but always willing. I accelerated a bit harder, got into top and saw 80 uphill without having to downchange, then dropped a cog to take a couple of tighter bends a little quicker than I had done going the other way, and settling down for the return run. Skirling between the undulating, pale yellow fields of stubble, I felt this was a wonderful bike, that would do anything you asked of it, in a deliberate but lively way. I knew that its potential was way beyond my skill set – I never was a scratcher – but I really liked it.

Conclusion 

When I switched off and walked around the Trident, there was not a spot of oil on or underneath it.

However, in the ringing silence, along with the satisfaction of a fine ride, there was a faint but potent sense of… Regretful nostalgia? After all the struggles in development and production – and they had been considerable – to bring this machine to its potential as represented by the late T150V, the model had then gone down to the dying of the industry’s light. On a personal level too, neither Peter or I were getting any younger – for me, near perfect riding days like these were numbered; and Peter told me that on health grounds, despite all the painstaking work he had put into them, both big triples would have to be let go before too long.

Meanwhile this Triumph is a bike to celebrate. Peter told me that the only major deviation he had made from its standard set-up had been to fit bigger main jets to the Amals, 160 rather than 150. “The reason?” he said. “Because it hadn’t felt right at first.”

It certainly did now, the mod likely contributing to engine’s liveliness that we’d both enjoyed. “That,” said Peter, “and the carbs being balanced properly. If you want reliable pickup and tickover with these, you’ve got to get the carbs right.”