Road Test: Triton test

Tri-umph engine and Nor-ton frame equals Triton, and this one’s immaculate

Everybody has a dream bike – the machine they’ve always wanted to own. Maybe it’s the bike they aspired to when they first got into motorcycling, the star of an Earl’s Court Show or a high street dealer’s window display, theirs for a price they could never afford. Maybe it’s the bike their mates were always talking about, the fastest production motorcycle ever, the one you could ride to a race circuit, take the lights off, race, and win. They were all going to get one next year, or the year after, you included – dreams and schemes fuelled by frothy coffee or several pints of Best. Maybe it’s a special, a flash of chrome, a blast of sound and the whiff of Castrol R, gone before you could get a really good look and so fast you were never, ever, going to get a second chance.

Mike Cookson’s early motorcycling may have been done on a lowly Bantam, but the bike world was changing fast in the late 1960s – goodbye Triumph, Norton, BSA, hello Honda – and the rest. Dreams, for the most part, were becoming attainable reality, and for a very long while he was the happiest of happy bunnies, owning a succession of oriental superbikes. All this was eventually to change, however. A regular diet of scurrilous rags like CBG nurtured a hankering for machines that clank and wheeze and bang, and in time he narrowed the field down to just two – a BSA Rocket Gold Star and a Triton.

Article continues below...

Enjoy more Classic Bike Guide reading in the monthly magazine.
Click here to subscribe & save.

Triton road testBut where would he find such exotica? Bikes that were advertised were either too expensive, a common phenomenon with dream bikes, or already sold – another common phenomenon. In a bid to turn up a hitherto undiscovered gem, he joined the local branch of the VMCC, only to find himself in the company of a dozen or more like-minded dream-seekers. He tried buying a box of bits – well, several boxes, actually – that purportedly amounted to a pre-unit BSA twin, with a view of building an RGS replica, but as is always the case the list of missing components soon equated to the size of a telephone directory. So in the end he employed the only practical tactic – patience.

News eventually filtered down the grapevine of a Triton for sale in Yetminster, North Dorset. It hadn’t run for about 10 years but it was complete; success at last, or so he thought! There followed a period of on-off decisions on the part of the vendor as to whether he would part with the bike or not, which was doubly frustrating for Mike as, having once seen the machine, he was already planning what he needed to do to it to turn it into his Triton. A deal was eventually struck, however, and Mike bought a new garden shed to celebrate – well, to house the new project, actually.

Tritons come in all shapes and sizes, that being the nature of the beast. The racing variety can be as minimalist as you like, providing there’s a Triumph engine in a Norton Featherbed frame with, I guess, a wheel at each end to keep things from dragging on the ground. Road-going versions, on the other hand, range from the purposefully pugnacious to the positively florid – just seek out a copy of Motorcycle Mechanics with the photograph of its project bike ‘Coloured Sound’ on the front cover if you don’t believe me. Personally, I think a bike with sporting pretensions has to be well engineered and devoid of junk – oddly shaped bits of glass fibre hung on with Jubilee clips just don’t cut it. And I’ve never been able to get my head around the concept of a ‘racing’ dual seat, especially one with a large hump at the back, designed, no doubt, to accommodate a toolkit and moderately-sized kitchen sink. Neither has Mike, so with spanner in one hand and the Unity Equip catalogue in the other, he set about putting matters right.

Article continues below...

Triton road testWith the glassware ditched he was left with a very practical combination of ’57 wideline frame housing T120 bottom end with T140 barrels and 10 stud head. The engine and standard Triumph pre-unit gearbox with four-spring clutch were held in place with alloy Converta engine plates. A very pretty, if slightly dinged, three gallon alloy petrol tank adorned the frame top rails and standard Norton hubs laced to 19in flanged Borrani alloy rims were fitted front and rear. Mike repaired the tank himself and had the wheels replaced with stainless spokes, then he added a rear frame loop, alloy mudguards and brackets and a Manx seat. The original long Roadholder forks were scrapped in favour of the short variety with external springs, mounted in new yokes with 7 3/8in centres – Mike chose the wider yokes to give himself the option of fitting a different front brake in the future, although he retained the John Tickle twin leading shoe backplate that had been installed by the previous owner.

The face-lift was completed with a new pair of Gold Star pattern silencers and clip-on handlebars from Unity, polished alloy Amal handlebar levers, and a chrome-plated headlamp shell from Bantam John’s stall at the Netley Marsh jumble. The speedo and rev counter were treated to new chromed bezels from Britbits and then mounted on an RGM alloy bracket. RGM also supplied the alloy rear brake backplate. The rearset footrest assemblies originally came from Rolston Precision Tooling in Oldham, and Mike subsequently modified them with rose joints from Barlycorn Engineering.

Triton road testThe Triton was beginning to come together the way Mike wanted, so, he figured, it was time to get it on the road and cover some miles. Unfortunately, the bike was reluctant to go along with this – it didn’t start well, it didn’t run well, and it vibrated a LOT. He broached the subject with the previous owner who insisted that it couldn’t vibrate anything like he claimed since, when he had rebuilt the motor, he had gone to great expense to have the crankshaft balanced. Still puzzled, but somewhat reassured, Mike resolved to work through a checklist of the more obvious problem areas.

Article continues below...

To start with, he exchanged the Mk2 Concentric carburettors for a handed pair of 932 Mk1s, discarding the cable operated choke slides. Happy with a noticeable improvement in starting, he entered the ‘Spirit of the Sixties’ run in early 2002, only to drop out with ignition failure. Whether it was the ignominy of coming home on a trailer, or simply the result of thinning patience, he ripped-out the Lucas Rita system that had come with the original bike and installed a Boyer Bransden set-up with MF battery. If that sounds a little drastic, his experience on the BSA rebuild had taught him that it was better to fit parts he knew and trusted rather than try to eke extra miles out of components whose past history was unknown. The Boyer sender was housed in a Kirby Rowbottom case and the electrical boxes and ignition coils were mounted on a platform underneath the front of the petrol tank. At the same time he fitted an L P Williams high output 12-volt alternator kit.

Up and running again – and this time things really were better, although the vibration was still there and it seemed to be getting worse. At this point, if you’ve ever been there, you’ll know how unhelpful the ‘how much vibration is too much vibration’ debate can be. Supporters will admit immediately that all British vertical twins vibrate, but after all, wouldn’t you expect them to? Isn’t that part of the bike’s character? Of course, some bikes vibrate more than others, you’ve just got a bad one, but you’ll get used to it. Detractors, on the other hand, scoff harshly at a motor never designed to displace more than 500ccs; at compression ratios better suited to a Clubman’s Gold Star; at a ridiculous riding position for a road bike – and the soaring price of a loaf of bread. None of which is in any way productive, and does absolutely nothing to allay fears that sooner or later something, that timely intervention could have avoided, is going to go seriously wrong.

Triton road testWhile fitting the new alternator, Mike had noticed a tiny amount of what he describes as ‘backlash’ in the crankshaft. Bearing in mind his attention to detail in all other areas, and not forgetting the earlier assurances that the bottom end of the motor was in the finest of health, we’ll all have to forgive him for not wondering how this could be, although after the drastic turn of events that was about to unfold, he often now ponders the fine line that divides trusting to luck from leaving nothing to chance.

Article continues below...

At a loss as to how to resolve the vibration problem, apart from securing his dentures with Blu-Tac that is, Mike entered the Triton on the local Velocette Owners Club Bob Foster Run with the prospect of a gentle amble around Dorset, rounded off by nothing more stressful than the choice between cake or buttered scone to go with the end of event cuppa. But for him there was to be no happy ending – the gremlin that had dogged the Triton from day one was about to rear its head, big-time. The crankshaft snapped across a big end journal, bending the connecting rods and smashing a hole through the crankcases. It hardly seems possible that such a catastrophe can be described in so few words, but there it is – no high drama chain of events, no high speed duel leading to a missed gear change coming out of the final corner before the start/finish line, just a pobble down to the coast and a blown motor.

Inspection seemed to suggest that the crankshaft had been broken all along, but because the break hadn’t been clean and because the two halves of the crank were effectively held together on each side by the crankcases, the engine had continued to run. Whatever the truth of the matter, it was back to the garden shed for some serious spanner-work.

Triton roadtestMiraculously, Mike was able to weld the crankcases back together – pre-unit T120 cases have been out of production for more than 40 years, remember – and Peter Dear from Trumpits in Bournemouth supplied a replacement crank from a unit motor. A needle roller bearing was fitted in the drive side crankcase half and Mike pushed the boat out (or should that be the plastic!) and bought a pair of forged 7075-alloy rods from Allens Performance in Nottingham and a rotary oil pump from Morgo. The ‘racing’ camshafts that had come with the bike looked well past their sell-by date, so they went in the bin and new E3134 Bonneville cams and cam followers were installed. That just left the wording of a very polite note to Santa Claus and the Boxing Day treat of fitting a Unity rocker oil feed and cartridge oil filter conversion, braided stainless oil hoses and a T160 kickstart lever – this last item, so Mike advises me, is much coveted among Triton owners due to the extra leverage it provides for spinning-up the motor; T160 owners be warned!

Not one to be defeated, as you’ve obviously gathered, Mike was back on the Spirit of the Sixties in 2003 and this time the Triton went the distance and picked up the trophy for Best Special. The pot stands on his sideboard next to one from his local VMCC section – Crank of the Month, awarded, following the Bob Foster episode, for most miles travelled in the recovery van. Hmm, the ups and downs of owning a classic motorcycle… And so you might well think that was that, but hardly had the Solvol Autosol sheen time to dull when the inlet valve pushrods broke. Now that’s an easy one to fix, or so you’d think, but the replacement pushrods broke, too.

Once more delving into things mechanical, Mike concluded that the ‘extra strong’ valve springs that had come with the original motor were the culprits. They had caused the excessive wear on the cams and followers, and, when the new cams had been fitted and the lobes restored to their correct height, the springs had become coil bound on full lift, overloading the pushrods. A set of Terry valve springs put matters right.

Triton road testSo, is this where our story ends? Mike’s Triton was now up together and running just as well as it looked, his dream of owning and riding a legendary special fulfilled. Well I’m not sure you can actually own your dream bike because effectively the dream then becomes reality. In any case, Mike feels there is still some way to go before the bike is just how he wants it. Or is that the outlook of all special builders, seeking to improve?

He has already tried a belt primary drive but didn’t like the set-up in conjunction with the crankshaft-mounted alternator. Possibly a little overcautious, although you can understand why, he also felt things were getting too hot for comfort inside the primary case without the cooling effect of the oil – all in all he was happier running a chain. He still plans to fit a different front hub – a four-leading shoe Grimeca unit when he can catch the bank manager in a weak moment. That will be coupled with a Triumph conical rear hub, drilled and modified to look like a Manx hub, and both wheels will be fitted with 18in rims so that he can use modern, sticky compound tyres. And, of course, he’ll need an extra-wide Mick Hemmings swinging arm with taper-roller bearings. But will there be anybody out there prepared to race, we ask ourselves. I expect if he waits long enough, some mad fool on a Norvin will turn up and rise to the occasion; after all, Mike has the patience. All I need is a Featherbed frame and a Lightening motor and a garden shed to put it all together in – dream-on sunshine! bike

Subscribe to Classic Bike Guide Magazine Enjoy more Classic Bike Guide reading in the monthly magazine. Click here to subscribe.