DRESDA TRITON
Chris Johns and his Triton go back a long way. Now his faithful old ride is back on the road with a Rickman eight-valve conversion, giving the power he always dreamed of
After 42 years together, Chris Johns has perfected his Triton. And we get to ride it
By any standards, a 42-year love affair is pretty impressive. Especially when it’s still going strong. But that’s how long Chris Johns and his Triton have been together – and they show no sign of parting any time soon. Together, they’ve travelled Europe and the UK and, though the Triton has gone through periods off the road and a number of incarnations, it’s essentially the same bike Chris put together in time for the long, hot summer of 1976. What makes a relationship last the course like that?
“I’ve always liked bikes that were a bit different,” laughs Chris. “My first bike was nothing special – a BSA C15 – but as soon as I passed my test I bought a Velocette Venom. That wasn’t what most students were buying back then – and I bought another one for £25, too. I was studying geology at university and had to go and work in the north of Scotland for a while, so I got into trials riding on a Greeves Scottish and then a Pathfinder. When I finished university, I wanted another road bike and it was then I discovered Tritons.”
While Chris’ mates were all blasting round on big Honda and Kawasaki fours, Chris stuck with the British bikes he’d grown to love.
“I bought an old 6T-based Triton,” he recalls. “And as soon as I’d got it, I rode it up to the north of Scotland. But I really fancied building my own, so I started stockpiling parts to do it.
“I found a place in London where I could buy MCN on Tuesday, a day before the official publication day, so I could ring the breakers and private sellers before anyone else. I bought a 1955 wideline Featherbed frame,
T110 crankcases, Bonneville heads, MKI Concentric carbs, Roadholder forks – it was all out there then. I got the exhaust built by a chap called Mike the Pipe, from Wallington in Surrey, with a Campbell silencer and splashed out on a hand-built tank from an old guy in Dartford who used to work for Lyta. I must have spent a fair bit on it, I suppose, but it went well – though the heads used to crack after a bit of sustained abuse.”
And abuse was what it got as Chris tried to keep pace with his mates on Japanese machinery. “I could out-do them cornering, but they’d just blast past me on the straights,” he admits. The Triton was never going to have an easy life with Chris, anyway. “I rode the bike to Norway when I was working on a project there,” he explains. “I converted it to street scrambler trim, with high ’bars and a sturdy rack. It was a sort of adventure bike before that genre had been invented, I suppose. I used to come back to the UK with 100kg of rock samples strapped onto the rack, but it stood the hammer – most of the time.”
The one time it didn’t was when Chris had gone on a touring holiday to Norway with a mate on the back. “The layshaft bearing went and we had to ride the last 100 miles in top gear. We made it home – just. The bike had magneto ignition and, even though the mag had auto-advance, I’d kept a manual advance/retard lever too, so I could retard the ignition massively – mainly for riding in snow. That helped us to limp back.”
Through the ’70s, the bike carried on giving faithful service, but Chris really wanted to put one over on his mates and their Japanese machines. “Around 1978, I started to pick up performance parts to build a Japbeating engine,” he says. “I bought a set of Bonneville crankcases, an eight-valve Rickman head and barrels, and a Norton-based stroker crank to bring the capacity up to 850cc. I wasn’t entirely sure about using that and bought a standard Rickman eight-valve conversion kit with overbored barrels that gave 688cc with a stock Bonnie crank as well. I came across a Robinson double-sided twin-leading-shoe front brake – I’d love to know a bit more about that, if any of your readers can help – and Lucas Rita electronic ignition kit, and stripped the bike down for the rebuild in the early ’80s. I had enough parts left over to build another Triton using the old T110 engine – I sold that to help fund the rebuild.”
But then life got in the way. By then, Chris had been to Zambia working for a number of years, got married and had a family. And the Triton stayed in boxes for almost 30 years as career and family life took priority. By 2014 though, Chris had wound things down a touch. His children had flown the nest, he was working part time and it was Triton time again.
“My original intention was to tackle the rolling chassis,” says Chris. “But, although I had all the major parts, I still needed to source or fabricate some components. And I wasn’t confident about building the eight-valve engine, so I got in touch with Dave Degens. He said he’d love to help and got very enthusiastic about the entire project. He persuaded me to let him handle the whole thing – though I had plenty of input along the way. The bike had been in bits for such a long time that I really wanted it done as soon as possible anyway.”
Dave convinced Chris that the standard Rickman eight-valve kit would be better for road use than the 850cc conversion and stroked crank, and supplied a stock T140 crank. He knows his way round a Triumph engine and he’s gone to town on Chris’s eight-valve special. “The crankcases are T120 and apparently came from the Triumph race shop some time in the ’70s,” says Chris. “The T140 crank is balanced to 82%, with a roller primary side main bearing and a ball race on the timing side. Dave reckons there’s little advantage to fitting a roller bearing on the timing side unless you’re riding mega miles, and using the ball race saves machining the crank. He’s fitted new, polished rods and a Morgo oil pump, too.”
Dave’s expertise shows throughout the engine. “The cam followers were fine, but Dave’s given them a gentle regrind to be on the safe side,” Chris adds. “He’s also drilled the timing wheels, though I fitted a new idler wheel and shaft late last year, and the cams are 3134 profile. The pistons and barrels are from the original Rickman ‘road’ kit; Dave’s lightened and polished the rockers, fitted his own lightweight valves and guides and used ‘elephant’s foot’ tappets with swivelling caps to reduce friction. On Dave Nourish’s advice, the head has been machined to accept copper head gaskets, rather than the copper rings that are standard on the Rickman head, and a thicker base gasket knocks compression down to around 8.5:1.”
The primary drive is a belt drive kit designed to fit a Velocette and using the stock Triumph clutch centre. “Dave Degens fitted 30lb clutch springs
‘DAVE DEGENS HAS REALLY GONE TO TOWN ON CHRIS’S EIGHT-VALVE SPECIAL’
at first,” Chris reveals. “But they weren’t up to the torque of the eight-valve engine, so he swapped them for 40lb springs. Late last year, I upgraded the clutch to a seven-plate version. The German-made 25mm Synchroflex GEN III primary belt runs dry – I have to grease the clutch rollers every now and then, but it’s worth it for the smoother take-up and gearchange action. I did have a set of close-ratio gearbox internals but, with the monster torque on tap, I’ve opted to stick with the standard ratios.” The carbs are 34mm MKII Amal Concentrics. “They’re harder to set up than the Mkis,” Chris concedes, “but the Mkis I had were the racing type with no choke. Dave’s fitted new ethanol-resistant floats, fuel shut-off needles and a #25 pilot jet and shortened the main needle slightly on advice from Dave Nourish. Dave has also modified the rocker feed – taking a high-pressure oil feed from the oil pressure relief valve on the timing case to feed the rocker direct rather than from the oil return lines.”
As for the rolling chassis, the swingarm, engine plates and oil tank are all Dresda items, while the forks are modified Roadholders with external, progressive springs and new stanchions, with the nearside pinch-bolt for the spindle concerted to a two-bolt clamp. The exhaust is another Dresda creation with stainless steel downpipes, while the bespoke alloy tank is from Chris’s original Triton build – as are the refurbished Chronometric clocks and Robinson front brake. Dresda handled the paintwork, wheel building – with new valanced rims and stainless steel spokes – and all the little bits and bobs that go into a quality Triton build. And, in late 2014, Chris’s beloved Triton was ready to hit the road again after three decades.
With the bike expertly set up by Dave and Russell at Dresda, Chris took it to HM Racing’s dyno in Edenbridge – and Chris was delighted with the results (see chart, right). “Even though I kept the revs down to 6000rpm for the dyno run, the results are incredible,” he beams. “You’d expect a stock 750 Bonnie to make 37/38bhp at the rear wheel. Mine hits 53bhp at 6000rpm. Dave Degens reckons it would safely rev to 7500rpm, so that would probably mean around 60bhp – enough for a 125mph top end. There’s stacks more torque than a standard bike. Maximum torque kicks in at 4000rpm and the ‘curve’ is flat all the way to 6000rpm from there, topping out just short of 48lb.ft at 4500rpm. Stock is around 35lb.ft.”
That’s very impressive. But what does that feel like on the road? Fast, is the answer. With compression knocked back to 8.5:1, starting the Triton is easy – just flip up the right-hand rearset before kicking it over. Once the 688cc engine is warm, it even ticks over and there’s no sign of any petulant behaviour, with loads of useable power from as little as 2000rpm. But it’s when the rev counter hits 4500rpm that things really start to happen. The bike pulls insanely hard through to Chris’s self-imposed 6000rpm limit. It’s a world away from a stock T140 – despite giving away almost 60cc.
The eight-valve engine continues to hurl the bike forward as the tachometer nears 6000rpm and I grab another gear – and another... and another. This Triton certainly doesn’t need a close-ratio gearbox, but maybe a five-speeder would add a little more to its top end. This engine would certainly pull a higher ratio in top.
The rest of the bike is what you’d expect from a build by ‘Mr Triton’ himself. The chassis is a perfect foil for the amazing engine. The Hagon progressive shocks at the rear complement the tweaked Roadholders up front and the wideline Featherbed frame lives up to its reputation perfectly. The Dresda swingarm, slightly longer than the standard Norton arm, gives a touch more stability and allows the use of a slightly wider section, sticky modern tyre, so I can throw the bike around with complete confidence. The Robinson front brake is powerful when warm, though slightly grabby when cooled off – but I’d soon get used to that. And the riding position, with slightly raised clip-ons, is on the right side of radical.
Has it all been worth it? The grin on Chris’s face when I ask him is all the answer I need. And my ride backs up his delight with the rebirth of the bike he’s owned and loved for so long. “I’m thrilled with it,” he says. “I’m so grateful to Dave and Russell at Dresda for doing such a great job. It’s all I hoped it would be. I love riding it and I’ve tried to do at least one long trip on it every year since it’s been back on the road. I took it on a touring holiday to Somerset the first year, then went to the Stafford show and back on it – via a rather circuitous 600-mile round-trip route – and went to Cornwall on it last year. I’ll have to think of somewhere to go this year.”
And next year – and the one after that. And... oh, you get it. Something tells me this superb Triton will be Chris’s favourite bike for many more years to come. Some things just get better with age.
‘THERE’S LOADS OF USEABLE POWER FROM AS LITTLE AS 2000rpm’