When his DMW appeared in RC back in 2009, lifetime motorcycle enthusiast and skilled restorer Roy Martin had just started collecting parts for a Vincent special. Roy is a fan of Paul Sample’s antihero biking cartoon character ‘OGRI’ whose favorite mount, of course, is a café-racer styled Vincent special. Roy’s idea was to build such a special as an OGRI tribute.
A great fan of Vincent’s gutsy 998cc V-twin engine, Roy is the proud owner of a 1951 Series C Rapide, which is his preferred daily ride – he doesn’t possess modern motorcycle. Naturally modifications have been made to improve the machine’s suitability for everyday use, the most apparent being the hydraulically-operated twin-disc front brake ingeniously fitted into the Girdraulic fork.
Of course Roy loves riding his bike (who wouldn’t enjoy a big VIN?) but, being an inveterate modifier and no respecter of sacred cows, he thought he could improve on the original concept. In particular he considers the Rapide to be a bit of a cosmetic nightmare, with a generally untidy appearance with fussy forks and rear suspension, a gap under the seat, and pipes and cables everywhere. Any motorcycle is entitled to sit comfortably in its own era and, as a basically 1937 design, the Vincent happily does that. When I began motorcycling in the 1960s, I misguidedly thought that Vincent’s had started to look a bit dated. Roy obviously sees it the same way.
So when he started planning his special, Roy’s objective was to achieve a‘clean’ looking machine, maybe even something that Vincent themselves might have produced had the company survived beyond 1955. Certainly a frame with swinging arm rear suspension and telescopic forks was needed, and an effort made to tidy the engine installation and ancillaries.
The Vincent V-twin has found its way into a good many specials and other applications over the years, so there was plenty of inspiration. Roy’s first step was to acquire the basis of a Vincent engine. These days, if your wallet is sufficiently deep it is possible to buy all the parts to assemble a brand new Vincent engine. The Nerving Centre in Essex is reasonably local to Roy. They were able to supply all the components needed to build up a complete unit.
Then a decision had to be made about the choice of frame to use. Roy considered a genuine Egli or a replica, but concluded that with those the engine sits rather too high in the frame to achieve the look he wanted. He next turned to that special builder’s favorite, the featherbed Norton. This solution appealed to Roy because Ogri’s Vincent special is often drawn as a NorVin, and of course such a special would have been possible back in the Sixties. It also appealed because there just happened to be a wide line featherbed frame and a set of Road holder forks tucked away somewhere at the back of the shed. So a NorVin it would be.
There are a fair number of NortonVincent specials about, so many of the difficulties and pitfalls have already been identified and solved. Roy knew that the Vincent engine and gearbox package has to be tipped forward slightly to get it into an unmodified featherbed. That solution didn’t appeal; he wanted the unit to sit level in the frame. Things can be eased by the removal of lugs from the back of the gearbox, but Roy didn’t really want to vandalize his power unit. He could have gone the whole hog and cut the entire gearbox off the back of the engine and used a separate one from another manufacturer. Unfortunately that approach creates more problems than it solves, because the primary drive has to be re-arranged and a chain case adapted or fabricated. The Vincent primary drive is by triplex chain, so Roy really wanted to use the Vincent clutch. It is designed to run dry, so cannot be used in an oil-bath chain case. There is also the issue of how to mount and drive the dynamo, which on a Vincent twin sits above the gearbox.
The more Roy contemplated that approach, the more he realized that it would be far simpler to extend the featherbed frame by three inches, so this is what he set about doing. At the same time, the frame was opened up by one-and-a half inches to accommodate a wider swinging arm, thus allowing room for a modern back tyre. The Road holder forks were refurbished, extraneous lugs removed, and spacers fitted above the springs to help them cope with the extra weight.
Once the frame alterations were completed, the Vincent cases were offered up and plywood templates made for the engine plates. These were laser-cut in 6mm alloy by a local engineering firm. The project was then dry-built on the bench to make sure everything fitted in and to identify and remedy any problems of interference or fit.
A nice five-gallon alloy tank was found on eBay and a neat oil tank was fabricated from alloy plate after much careful work making up cardboard templates. Roy was particularly keen to achieve the neatest and most tucked-in exhaust layout possible, and came up with the novel idea of running the pipes from the two cylinders between the engine plates. Careful work with foam pipe insulation established that that such a layout was possible, so Roy finalised the bends he needed and got them made up by Competition Fabrications in Norfolk.
Thefinished exhaust is oneof the visual delights of this machine. Both pipes disappear neatly between theengine plates in front of the crankcase, then run back beneath the engine, where they join toemerge as a single pipe which terminates to the left of the wheel spindle. The pictures showjust how neat and ingenious the exhaust is. The pipes may look as if they’d beanightmare to remove or replace, and Roydoes admit that the job is likea‘Chinese puzzle’, however aswithany puzzle if youknow howtodo it you can. Roy assures me it takes no more than tenminutes to remove or refit them.
After persuading the engine to fit into the frame, and having established that all the ancillaries lined up, it was then time for Roy to turn his attention to assembling the best Vincent engine he could.
The intention all along had been to build the special as a café racer showbike, but with a view to eventually putting it on the road. But so far as the power unit is concerned I reckon Roy got a bit carried away. These days many Vincent tuning and racing parts are available, so the engine was built up pretty much to racing standard.
Into the brand new crankcases went an Alpha crank and flywheels. A pair of Carrillo connecting rods on caged-roller big ends support 9:1 Omega pistons (the standard Shadow compression ratio is 7.3:1). Twinplug cylinder heads are fitted to improve the flame front travel in the large combustion chambers. Standard-sizeVincent valves were fitted – Roy reckons they’re quite big enough already – and the ports were gas-flowed and polished. Terry PrinceMkIV camshafts (high-lift, racing spec) came all the way from Australia and the cam followers were given a ‘Diamond-Like’ hard carbon coating.
The standard specification Vincent primary drive, clutch and gearbox fitted used new mainly parts. As Roy puts it, ‘the clutch is about the only original Vincent component in the bike’. The machine retains the somewhat dubious Vincent dynamo drive – a sprocket engaging the outside of the centre run of the triplex primary chain.
Carburetors are32mmAmal Mk1 Concentric, just1mmlarger than the Black Shadow’s standard11/8”Monoblocs.Mk2 Concentric were considered, but Roy decided they took up too much space and looked wrong.
After the first build, the bike was stripped back to a bare frame which was then sent away for powder coating. All the right bits were polished or went for chrome plating. Alloy wheel rims were built onto BSA / Triumph conical hubs using heavy-duty stainless steel spokes. The eBay tank responded well to a polish and paint, ready to be set off by a chromed central retaining strap.
Once the frame was back, looking good in its black powder-coating, the meticulous build-up could begin. The first stage was to fit the swinging arm, forks and wheels, followed by the engine and gearbox unit. The ease with which things went together demonstrated the value of the dry build, and soon Roy was looking at a competed special.
Eventually the day came for the NorVin’s first start-up. As expected for a new, tight motor, it didn’t want to respond on the kickstart. A set of rollers were dragged out, a friend’s Fiesta was pressed into service to get things turning and the Vincent engine soon burst into life. A brief ride established that everything worked as it should, but the unsilenced exhaust was rattling surrounding windows so the prudent decision was taken to curtail the testing. Roy then fittedamute into the end of the pipe, which did quieten things a bit; but not much. But it ran – and ranwell!
The NorVin made its showdebut at the 2014 Copdock Show and Roy was delighted when it won both Best Café Racer and Best British Bike awards. The bike thenwent to Kempton Park and to Stafford, again attracting a great deal of interest.
For our photos, we took it to parkland surrounding aThames-side nineteenth century fort. I was dying to have a go, albeit under restricted circumstances because the bike is not yet road legal. I can say that the riding position is pure café racer with the rear-set footrests and clip-ons dictating a near-racing riding position. Not particularly practical for riding distances, but it felt pretty cool.
Although confined to private ground, we were still determined to start the beast and let it loose. Starting it promised to be a fairly daunting process. A Vincent 1000 with 9:1 compression ratio takes a bit of kicking over. As always there’s a procedure. Fuel on and let the BT-H magneto’s electronics take care of ignition retardation. Tickle the carbs, open the valve lifter and give a long swinging kick, releasing the lifter halfway down the kickstart stroke. Once the big flywheels aremoving it will go over the next compression. Then it catches and bursts into life with an angry crackle from the open, if ‘muted’, pipe.
The racket and the vibration all serve to convince that this is a machine which means business. Pedal up to select first. It goes in with just the suggestion of a clonk and we’re off. For a heavy machine with a café racer riding position it actually feels completely tractable and balanced as it pulls away. But we are talking about first gear circles around a car park here; just a frustrating quarter-turn of the twist grip away from the grunt that was waiting at the other end of the wire. But not this time. Riding it properly will have to wait until Roy has got it on the road.
RoyMartin’s NorVin certainly is a labour of love. He built it to be his vision of an ultimate NortonVincent special. As with any special it is still a work in progress. Roy recognises that even twin leading shoe brakes in conical hubs are unlikely to be up to the job, and he’s not quite sure if the Roadholders will be up to it either, so he’s taking a fresh look at the front end with Ceriani forks and a four leading shoe front brake planned.
And the Ogri tribute aspect? Roy’s everyday HJC full-face helmet, sporting Ogri artwork, tells its own story. He is a true fan. He even considered naming the bike ‘Armageddon’ as a further nod to Paul Sample and Ogri. But the plan now is to go for a straightforward NorVin decal. Anyway, this magnificent creation speaks for itself.