There are no stiff and graceful BSA or Norton-style duplex loops here; just a boringly straight down tube, united with a flat base section by an old-fashioned brazed lug. Further aft, the swinging arm pivots in a heavy casting that’s fixed onto the saddle tube, with little other than the brazed joint to stop it swivelling. Even the swinging fork itself is hardly a masterpiece of rigidity, as its two arms simply clamp onto the ends of a pivoting bar after it has been slid into a cross piece.
Fortunately, the owner of today’s test bike is in full agreement. “Yes it’s pretty obvious that the front section is similar to that on the old rigid frame,” says Velocette fan Neil Redley, “and that the swinging arm section has been tacked onto the back. Even the forks were little changed from first to last.”
Nevertheless, it’s common knowledge that it all worked pretty well. In fact, it worked amazingly well when you consider that the frame intended for the 1953 MAC eventually had to cope with almost three times as much power from the Thruxton Venom engine. Obviously the geometry must have been spot on, but equally importantly, having a compact frame wrapped tightly around a narrow engine enabled Velocette to get away with a construction technique that simply wouldn’t have been rigid enough for a lankier chassis. Even being charitable, though, I’m at a loss to explain how those frail forks – we’ve all seen them swishing backwards and forwards wat tickover – managed to cope.
Neil and I are obviously not alone in our doubts, and over the years many specials have been constructed to improve on the standard set-up. The most common upgrade, naturally, is to install the Velocette engine in a Norton Featherbed frame, and Neil also has one of these (christened a Norcette, rather than the more usual Velton) while I reported on another one in TCM in July 1998. More radically, a specialised frame can be used, and the Rickman brothers supplied kits for Velocettes.
There were other specialised frame makers, of course, and one of the most highly regarded was Colin Seeley. Seeley had initially become famous as a sidecar racer – he was British Champion in 1962 and 1963 – but paradoxically he became better known as a manufacturer of frames for solo racers.
Starting in the mid-1960s he made bronze welded frames of Reynolds 531 tubing for AJS and Matchless racing engines, and shortly afterwards bought the defunct AMC racing department and the right to the future manufacture of the 7R and G50 racing engines. The frames gave the aging ohc singles such a new lease of life that Seeley’s rider, Dave Croxford, became British 500cc Champion in 1967 and 1968. The following year Croxford came under the patronage of dealer Gus Kuhn, but retained the championship on a Seeley.
It’s actually misleading to speak of the Seeley frame in the singular, as there were numerous developments. The earlier variants featured full duplex loops, where the rear ends of the top members were sloped downwards towards the swinging arm pivot to provide extra stiffness. That principle was carried further in the MkIII, where the tubes between headstock and suspension pivot were almost straight, with an AMC race engine suspended beneath the trellis. Famously, in 1971 Seeley used this frame to produce a few examples of the Condor – an exotic road-burner powered by a slightly detuned Matchless G50 motor.
Following the amalgamation of his company with the manufacturers of Brabham racing cars in the early 1970s, Colin Seeley became increasingly involved with four-wheeled racers, and after a very successful spell making further modified frames for the Yamaha-powered Yamsel, gradually withdrew from motorcycle sport. He still, however, produced relatively conventional Seeley frames that could house most of the Japanese power units, besides the few remaining British ones like the Norton Commando. Official production eventually ceased, but because it’s virtually impossible to copyright the design of a set of steel tubes bronze welded together, other ‘Seeley’ frames have since appeared.
To return to my original theme, if you are a Velocette fan looking for a better chassis to house your power unit, why not choose one that literally has a proven track record? That’s what marque devotee Dr Peter Connor thought, anyway, and unlike many pipe dreamers, he acted on his thoughts. The 2003 Classic MotorCycle Show at Stafford gave him the start he needed, and he returned home with a MkII Seeley frame that proved ideal to house a Venom engine prepared to full Thruxton spec by fellow Velocette enthusiast Tony Mortimer.
Dr Connor then complemented the motor with an AMC-Norton gearbox – already regarded as the best classic unit – which he further uprated with a five-speed cluster from Norton specialist Mick Hemmings. At the front end, he ignored the easy option of Japanese forks already fitted with powerful twin discs, and opted for the excellent telescopic legs from a Norton Commando, clamping them into Seeley yokes.
The result is now owned by another equally enthusiastic Velocette fan – Hampshireman Neil Redley – and today I’m having the considerable pleasure of having a spin on it. Wow! I could sum up the experience by saying that it delivers all that it promises, but that would be a cop-out, so I’ll put flesh on the bones.
Firstly, and most importantly, the frame epitomises the difference between a roadster and a racer. Normally, when approaching a corner, you subconsciously slow to the point at which you feel that the frame will keep the wheels pointing in approximately the correct direction without the suspension wallowing or lurching. With a frame like the Seeley – and quality ancillaries like the Maxton rear shock absorbers – such considerations are secondary. You simply know that everything will stay in shape, and that the only limitation to the speed you travel through a corner is your nerve and the tyres’ adhesion.
Of course, the old ‘no pain, no gain’ adage is as true in motorcycling as anywhere else. The frame’s stiffness is partly the result of its low compactness. Couple that with footrests set high enough (barely a foot below the seat) not to degrade that hard-won cornering ability, and you’d do well to practise the Yoga Lotus position before attempting to ride this machine! The neatness also means that a big chap like Neil is never going to tuck himself entirely away out of the airstream. And the clip-on handlebars naturally put an uncomfortable amount of weight on the wrists and forearms, so you’ll feel as if you’ve been in a boxing match after your ride.
Let’s get all the ‘pain’ aspects out of the way at once, shall we? Velocette engines are normally noted for their smoothness, but that’s not the case here. Whether it’s an incidental result of the frame’s relative lightness, the way in which the engine’s mounted, or indeed whether this particular engine is out of balance, I don’t know. But I do know that the combined effect of the vibes felt through the bars, and the strain of supporting my body weight, made me happy for traffic hold-ups to afford an occasional opportunity to shake some circulation back into my hands.
But traffic is not where you want to be with a bike like this. “Give it a blast down the dual carriageway,” said Neil, and I didn’t need to be asked twice.
Now, if you’ve never ridden a highly tuned single like a Thruxton, a Gold Star or an International, you’d probably be surprised – and perhaps disappointed – by the experience. There is little of the kick in the back you’d get with, say, a Commando or an Interceptor. Instead (and provided everything is in perfect tune) there is a continuous push that gets you to very high velocities surprisingly rapidly. I won’t say what speed was indicated on the bicycle-type electronic speedo, but when I reported to Neil that I was holding 6000rpm in top gear he mused that he’d have to recalibrate the speedo because it was obviously reading a good 20mph too low. Suffice to say it’s lucky that I didn’t pass any police cars or speed cameras!
The point is that a well-prepared and highly specified machine like this feels as safe and stable at high speeds as a lesser one does at a more pedestrian pace. That might sound like stating the blindingly obvious, but I assure you that some of the potentially fast machinery I’ve ridden would only be enjoyed by a prospective suicide case. As with the feeling of security during cornering, the Seeley frame and its high-quality ancillaries gives complete confidence in a straight line. A hydraulic damper is mounted directly onto the forks (the bikini fairing has a quickly detachable mount where Velocette’s damper used to be) but I get the impression that it’s far from essential.
Those impressive looking brakes at both ends do the business, too. “The four leading shoes on the front one are obviously in adjustment,” I remark, “is it difficult to set them up?” “I’ve no idea,” Neil replies, “that’s how they were when I got the bike, so I’ve left them well alone.” Sensible chap, and a generous one, too, as it’s only later that I learn he’d only ridden the Seeley 50 or 60 miles himself before letting me loose on his considerable investment.
Now then, what about the perennial complaint that Velocettes – especially the hotter ones – can be difficult to start? Well, this one is a bit of a Jeckyll and Hyde, as it either fires up with the first prod, or you need to round up some muscle and supply them with running shoes.
In fairness, more familiarity would probably improve the situation, especially as the Thruxton engine is fitted with a modern BTH magneto, and a civilised MkII Concentric carburettor. That, incidentally, was the carb worn by the last factory Thruxtons, as the Amal GPs used previously were almost impossible to obtain, and Velocette’s remaining stock had been stolen! The standard Velocette silencer may not fit the modern streamlined image of the Seeley, but a Velocette without a fishtail wouldn’t be the same, would it? It certainly wouldn’t have that wonderful thumping exhaust note.
Starting – and indeed riding in general – is made considerably more user friendly by relegation of the temperamental and over-stressed Velocette clutch. Primary transmission is now via a Bob Newby belt drive and multi-plate clutch, so it is noiseless, effective, and leak-free!
For some reason the gear change mechanism has been taken to the left foot via a complex array of rose joints, and that could well be responsible for the occasional false neutral appearing between fourth and fifth. Unless the set-up is essential to give clearance for the pivoting kick-start lever, it would be well worth reverting to a simpler right-foot system.
The low voltage electrics are often criticised on original Velocettes, and here an Alton generator has replaced the dynamo – a popular upgrade on Miller equipped bikes. It’s still rotated by a belt, and the belt is still protected by an offshoot of the primary drive cover. An alloy oil tank occupies the space where the 12-volt battery would normally live, so it has been tucked down behind the gearbox. It’s a solution frequently employed on specials, but Neil wasn’t overjoyed to find that battery removal requires prior dismantling of the clutch!
He has few other complaints, and I’m not surprised. His bike may not be very comfortable, and its temperament would hardly make it anybody’s first choice for a trip to the shops. You might very well pooh-pooh the whole concept of a racer on the highway, and lord knows the speed potential of such a device is irrelevant and anti-social on the vast majority of our roads today. But, unless you can honestly say that you don’t like the look of the Seeley-Thruxton, and that you wouldn’t fancy a spin on it yourself, you can only join me in envying Neil Redley having it in his collection.Enjoy more The Classic MotorCycle reading in the monthly magazine. Click here to subscribe.