Triumph Twenty-one
No, not a big birthday, but a Triumph-loving lady’s first foray into Meriden’s unit twins.
Angela Cotton likes Triumphs. You may recall our article on her Tigress 250 scooter, and another on her Tiger Cubs (TCM, November 2019).
Six years ago at Netley Marsh autojumble she upped her game, purchasing a 1961 3TA 350cc twin. “I’d always fancied a bigger Triumph,” she said. “I really wanted a 500, but this was within budget.”
“Though you’ve spent the difference and more since then,” laughed Angela’s partner Graeme Stretch. He’s into Triumphs too, though in his case it’s the classic four-wheeled kind, and he has helped with many of Angela’s rebuilds.
The 350 from the trader turned out to have been bodged together with several non-original and ill-fitting parts. This was to be a practical, ridden machine, not a show bike, so the lack of detail originality didn’t bother Angela, but the mechanical problems did. Pegging away at them, plus using and working on her scooters, ancient and modern, has meant that the Triumph has covered less than 500 miles since she’s been its keeper, and not left its Isle of Wight home.
Angela is a good-humoured and capable woman, and her love of the Tigress and her Vespas chimes with the story of Triumph’s Twenty-one, a historically significant model – and one with a big link to scooters.
The tale of the Twenty-one
The 350cc model introduced for 1957 was Edward Turner’s first unit construction twin. By 1963, all Triumph parallel twins would be to that configuration. So this was a big step for Meriden, and the new model, though mechanically similar in many ways to the previous twins, differed in others. Compared to the previous pre-unit 3T 350 with its 55x73.4mm dimensions, discontinued in 1951, the 349cc (58.25x65.5mm) Twenty-one was short-stroke. The 3T’s long stroke for its small bore had caused its con
rods to flex, as well as whip in its crankshaft. This had contributed to unsatisfactory performance.
By the mid-1950s Meriden had a new chief engineer, former Rolls-Royce man Charles Granfield. He and John Nelson, then head of the development department, laid out the new machine to Turner’s requirements in secret at Granfield’s home, and carried out a 20,000 mile roadtesting programme. The result was an understressed engine which would often be noted for its high mileage working life. Its coil ignition system was already a feature on bigger utility twins like the 6T Thunderbird. Though the 350’s distributor was a potential weak point, when new and in good condition, the system could provide easy, reliable starting.
But the initial impact of the Twenty-one was its appearance. This expressed visually the underlying philosophy on Turner’s part behind the model, which consisted of two interlocking strands. Like several other designers, Turner had long been interested in producing an ‘Everyman’ motorcycle which would sell in bulk to non-enthusiasts. He had patented a 1945 3TU (for Utility) 350cc twin prototype, featuring disc wheels for easy cleaning and very big mudguards for weather protection, but its hot-running, underperforming engine had put paid to it.
By the 1950s, a two-wheeler existed which did have genuine mass appeal to non-motorcyclists. By the middle of the decade, imported scooters, together with mopeds, were outselling motorbikes. It’s hard to exaggerate what a fresh, universal social phenomenon scooters became. Turner, who would initiate an (unsuccessful) scooter division for BSA/Triumph in 1957, earlier had combined his utility bike thinking with the notion: “Why can’t a motorcycle be more like a scooter?”
The scooter features he sought to incorporate into the Twenty-one were weather protection, the masking of menacing mechanicals and noise, and the appeal to young people, including female ones, with relatively light weight, low seat height, and colourful finishes.
The 350’s rear panelling (quickly dubbed ‘bathtub’ due to its resemblance to an upside-down hip bath), its fully enclosed rear chain and its voluminous ‘fireman’s helmet’ front mudguard, gave weather protection as well as partially covering up ‘the works’; they also soon provided a canvas for two-tone colour schemes. The unit engine with built-in alternator was less obtrusive and cluttered than a normal pre-unit’s separate engine, gearbox, magneto and dynamo. Attention was paid to effective silencing, and the use of 17 inch wheels lowered the seat height to 28½ inches.
Beneath it all, however, lay a fundamental misconception. The scooter, as Jon Stevens pointed out in his book “Scootering”, had created a new market. It was for just relatively stylish, undemanding transport, with an effective service network in the case of Lambretta – not “spare time mechanical problems.” And under the Triumph’s panelling was still a motorcycle, and one from which the rocker caps would detach themselves and release oil, one where the chains had to be kept adjusted (and the 350 had no primary chain tensioner until 1961), or the duplex primary chain would clang alarmingly on its case. And so on.
Still, the British industry had been wrong-footed by the roaring success of scooters, and unerringly successful Mr Turner’s thinking sounded good
“The British industry had been wrongfooted by the roaring success of scooters.”
to them. There had been no show in 1957, and the eagerly anticipated one in 1958 trumpeted “Look At The Future. Enclosure. Colour. Lightweights.”
The completely enclosed 250cc Ariel Leader made its debut. The first of Norton’s responses to the new Triumph, the unit ‘Light’ twin Jubilee, an unsatisfactory 250, duly appeared swathed in two-tone panelling. And a regiment of British two-strokes followed suit. Motor Cycling’s columnist ‘Carbon’ concluded that “this Show will go down in history as the one where the scooter and motorcycle finally met.”
Twenty-one to 3TA
The Twenty-one name had been to celebrate the 21st anniversary of the Triumph Engineering Co’s foundation. Coincidentally, in America, a growing market, 350cc was rendered as 21 cubic inches. From September 1958 Triumph’s Twenty-one was also dubbed the 3TA, as part of Meriden’s C-Range, which now included a 5TA Speed Twin unit 500 version. It too was panelled, as would be the T100A sports version; a sports 350, the Tiger 90, would not appear until 1963. Soon the 650cc T110 and 6T were swaddled in stamped steel too. Turner had no time for self-doubt.
Triumph’s 3TA 350 weighed in at 340lbs dry, and produced 18.5bhp@6500rpm. The price in 1958 was £228, when an Ariel Leader cost £209, a Norton 250 Jubilee £215, and a Lambretta TV 175 £209. So the 3TA was competitive, but not quite a bargain.
The 350 engine, with iron barrel and alloy head, was housed in a chassis which Meriden admitted derived from the Tiger Cubs. Like them, it featured a dropped tank rail which at its front end bent upwards to run parallel with the single front downtube, making the 3.5 gallon petrol tank a partially stressed member. Unlike the Cub however, the rail was then raised into a heavy ‘swan neck’ steering head lug, which was under-braced and gave a steeper steering head angle of 66¼ degrees. This frame provided handling which was acceptable in everyday riding, but not when pushed.
The front forks were two-way damped for the first time. The ‘fireman’s helmet’ front mudguard was the forks’ only bracing, which subjected it to stress. Split front mudguards and petrol tanks were not infrequent, though the single carb engines with their modest 7.5:1 compression rarely gave trouble. Top speed on test was 82mph.
For 1961, the 3TA was fitted with a messy and unsatisfactory flat-spring blade primary chain tensioner. The seven inch brakes, full width hub at the front, became fully floating. The whole C-Range saw the chassis’ steering head angle steepened by two degrees. This was aimed, without affecting road handling, to improve cross-country performance in the US. For the US competition unit 500s, there was also an additional frame-stiffening strut, bolted into place under the fuel tank, to triangulate the frame’s upper section. This didn’t reach the roadsters until 1965, but can be retrofitted to the 1961 to 1964 C-range chassis.
The American market was becoming increasingly important to Triumph as the UK home market collapsed. And US riders did not like the bathtubs. As authors Brooke and Gaylin note in “Triumph In America”, the panelling, “To sports-minded Americans… did all the wrong things. It made the motorcycles look heavy and boat-like. It hid critical nuts and bolts, detracting from serviceability. Worst of all, it made the machines appear ‘unmanly’.” They described “piles of bathtub enclosures” removed and “stacked up behind major US dealerships.”
“The report in The Motor Cycle predicted the 1958 show would go down in history as the one where the scooter and motorcycle finally met.”
It wasn’t just America. In the UK from 1958, the percentage of 20 to 25-year-old motorcycle buyers rose above 40%. Many of them were rockers, actual or wannabee, who had the same objections to enclosure as the Americans. Beneath the 3TA’s hinged seat, for instance, there was a pre-formed tool tray, so you could only carry the limited factory tools until 1960, and after that just a small tool roll.
Removing the left-hand panel to clean the air filter, involved taking the seat off its hinges, undoing a screw at the front, the upper pillion footrest nut, two screws in the top rear frame tube and a further pillion footrest nut, and finally disconnecting the rear lamp wiring. By contrast on a Vespa, clicking one catch let you remove an entire curvaceous side-panel to reveal the whole engine!
The panels would progressively shrink to ‘bikinis’ by 1964 when Turner stood down, but by then motorcycle styling had moved in an American direction, and that 1958 Show vision had vanished. Not before, as Brooke and Gaylin pointed out, it had “cost Triumph incalculable lost sales in its biggest market.” They called the bathtubs “the company’s first major-league foul ball!”
Angela’s answers
Angela Cotton is a methodical person, and she set about rectifying her cobbled-together 1961 350. A principal problem area were the front forks, where incorrect parts had been bodged dangerously to fit. She progressively replaced the springs, bushes, top and bottom steering yokes, the nacelle top and the nacelle legs. The chromed sliders too are wrong, but originals have yet to be substituted, and meanwhile they leak stubbornly from their bottom screws.
Practical substitutions have included later versions of those pesky self-detaching rocker box inspection caps, which had retainer clips. They were part of a full top end rebuild last year. The distributor meant that the timing could slip, so the timing cover was swapped to one with a detachable inspection cap, “so you could actually time it!” before fitting the ultimate solution, electronic ignition. A new 375 Monobloc was sourced from Burlen Fuel Systems. The speedometer, which had been incorrect and in kilometres, was rebuilt by Ashley Pople in Aldershot (Tel: 01252 329826), who Angela has used a lot; and the pattern ammeter replaced with a correct Lucas one.
As mentioned, this is not a bike for strict originality. The exposed spring rear units are late 1960s’ style, and the upper tank colour, which should be Shell Blue, is “not correct, but appropriate.” One area where Ms A did intervene was in ditching the glass fibre replica rear panels and front mudguard in favour of genuine if distressed original steel items. Not too easy to find with so many having been junked back in the day, but definitely the right move.
A final restoration drama came the night before our test. Angela had the 350 back together and was finishing up, working to seal the fork drain screws with compound. Then she smelt something which she thought at first was somebody burning plastic rubbish, before noticing smoke from under the saddle. A wire had been trapped when the tank had gone back on, and the fuse-holder was melting. Luckily Angela had the necessary spares, and disaster was averted.
The Future Past
Switch on the Twenty-one and it started second kick with little effort involved. First impressions were of a lady’s model, in that the footrest and down-for-first gear pedal were close together, but this proved only a temporary set-back.
Having cleared the light clutch pre-startup by a traditional couple of kicks with the lever pulled in, gearchanging was smooth enough. The seat and riding position, compact but not cramped, were comfortable, and there was very little vibration from the small twin. The seven-inch brakes worked satisfactorily, though Angela had joked that this was only until you really wanted to stop! The engine felt quite low-geared and pulled well if not spectacularly, lacking low-down torque but picking up well from the mid-range in third, and it was flexible enough so that on the Island’s A-roads you rarely needed to get out of top. There was no sensation of weight or vulnerability to side-winds from the rear panelling, which you quickly forgot about.
The winding roads soon asked questions of the handling, and the answers to these were mixed. Angela is still unhappy with the front forks, and another factor might have been the tyres, which have yet to be replaced; Angela describes the front one as “old, and square”. My own reservations also centred on the front end, but more in terms of the goose-neck frame. There was a sensation of imprecision there which discouraged radical angles of lean. Yet I went through a set of right/ left bends steadily on a rising throttle at a sensible 40 increasing to 50, and there was no problem. But do you buy a Triumph twin to be sensible? It was just that my own first motorcycle had been a panelled 350 twin, a 1962 Norton Navigator, and with Roadholder forks its cornering had been definitely more confidenceinspiring.
On straight stretches you had to work to get the 3TA to an indicated 60, with no more readily available. But this was a 60-year-old, low-tuned machine. And as Angela said, she hadn’t bought it for speed: “I have more modern scooters that are faster!” So horses for courses. The Triumph suits the owner, and it suits the Island. If it seemed like a machine that did everything adequately but nothing outstandingly, there was one exception. From today’s perspective its looks, with the panelling and matching front mudguard, in the metal were a pleasing mix of the strikingly unusual and of fundamentally graceful lines. In that respect Edward Turner had got it right first time.