Nowadays the term ‘Bobber’ has become as ubiquitous as café racer or street tracker, with manufacturers jumping on a potentially profitable bandwagon.
But Fred Walmsley, 71, is old enough to remember genuine Bobbers first time around, when they were created in the USA post-Second World War.
After toying with the idea of building one for 50 years, he’s finally gone and done so in the well-equipped workshop attached to his farmhouse on the edge of the Lancashire fells. Except it’s not a Bobber, it’s The Fredder – as in, built by Fred, not Bob, using an array of Norton parts to create a cut-‘n’-shut, street-legal, vintage racer with heaps of attitude.
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This Anglo-American concoction sits well with the 1952 straight-six, ¾-ton Chevy pickup it shares the Walmsley farmyard with, or the 1931 Model A Ford hotrod nestling in a nearby stable that’s been channeled and chopped to produce a totally authentic 5.7 litre flathead V8 speedster.
Yet Walmsley – aka ‘Kentucky Fred’, on account of the KFC franchises in nearby Blackburn that he made a good living from before selling up to concentrate 100% on fettling motorcycles of a certain age – is best known for the succession of Manx Norton and Matchless G50 classic racers he’s furnished over the past 25 years. Barry Sheene, Wayne Gardner, John McGuinness and other stars past and present have all ridden Fred’s bikes. Together, they’ve won dozens of historic races around the world from the UK to Australia with Walmsley-prepped bikes, all of which were prepared in that same farmhouse workshop. But this isn’t a racer, so what’s with the Fredder, err, Fred?
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“I’ve always liked building stuff like this,” admits Walmsley, “ever since the early 1960s when at 14 years old I built what you’d now call a mountain bike out of my pushbike. My mum has a picture of me with this creation, complete with wide handlebars, moped wheels, big tyres and stuff like that. I had it in my mind for a long time to build a Bobber-type hotrod to ride around on, but it wasn’t till I came across an ideal donor bike that I finally got going properly on it, about two years ago.”
That bike was a 1952 ex-police Model 19 Norton, a 596cc ohv single built from 1933 onwards by the Birmingham-based brand, primarily as a sidecar tug – hence the capacity, and the four inch-plus stroke. But Walmsley didn’t plan to use its ultra-longstroke 83 x 113mm pushrod motor as the basis for his Bobber – sorry, Fredder – he just needed the extra height in the frame delivered by the tall engine to install a longstroke Manx Norton cammy motor, suitably revamped for road use but without being detuned. Well, you wouldn’t expect the King of Classic race tuners to stick just an ordinary Norton ohv engine in it, would you?
“I raced a Formula 3 Cooper car for a few years, and it had a longstroke Manx Norton engine with the Alfin big-fin cylinder they all used back in the 1950s, because the engine was stuck behind the driver, so there wasn’t such a good flow of cooling air as in a bike,” explains Fred.
“I really liked the look of the engine with that meaty cylinder finning. I think the barrels look really weary on the original-type long-stroke Nortons, whereas the big-fin engine reminds me of a bulldog puffing its chest out. In fact, I’ve had my own barrels made with slightly bigger finning still, so as to match the larger longstroke cylinder head with the long cambox. I think the way the Fredder’s engine has come out, it’s a piece of mechanical art that’s beautiful to look at – even more than the later short-stroke motors.” Hard to argue with that, isn’t it?
To show off this mechanical centrefold pinup, Walmsley has created a replica of the works Manx Norton engine world champion Geoff Duke defended his title on in 1952. He took a set of replica longstroke (pre-53) Manx Norton crankcases cast in magnesium, surmounted by the special cylinder barrel he had made with extra finning, which has a Nikasil chromed bore. But rather than retain the
79 x 100mm dimensions of the 500cc customer version of that engine, he chose the ‘square’ 86 x 86mm layout of Duke’s works engine as adopted on later short-stroke Manx singles. To achieve this, Fred used a modern one-piece crankshaft with white metal plain bearings and Cosworth shells, carrying a Carrillo steel rod, topped by a forged Omega piston, delivering a 13:1 compression ratio. “The piston’s a bit of a hybrid design, because it’s got the same hemi shape as the longstroke Norton one, but with a squish band on the side like on a G50,” says Fred.
“It works really well, though I had to get 10 of them made as a minimum order. So we’ve got some spares!” The longstroke Manx cylinder head is a one-off casting furnished by Preston neighbour Molnar Engineering, with a special combustion chamber to suit the hybrid piston, but stock valve angles to match the cambox. Walmsley then hand-ported the head to his own spec, but the nimonic valves used in the Fredder are actually slightly smaller than those in even a standard longstroke Manx engine, let alone a bigger-bore works motor.
“Most of the gains I’ve had with replica Manx and G50 engines have come through the exhaust side of the cylinder head and the exhaust system,” says Fred. “I think Nortons lost their way with that side of things, because for them it was all about inlet tracts, compression ratio, valve overlap and all that. I think the valves were too big in the Manx engines to give the right harmonics, and especially the exhaust valve and the exhaust port. I’ve actually downsized from stock on both inlet and exhaust valves, but the actual volume and area of the exhaust ports on Manx engines that I tune are probably 50% less than what Norton was doing. They’re very small – people look at them and say, that won’t work. Okay, then – but just try and catch my bikes out on the track!”
Those smaller valves carry hairpin springs – often a recipe for oil getting splashed on your boots and even the rear tyre. “I’ve used hairpin springs because they look nice, and these don’t pass a lot of oil,” he says.
“A good friend of mine was in charge of the tool rooms at British Aerospace here in Preston before he retired, and he’s an old-time jig borer. So instead of reaming the pusher bushes and that, we made a fixture and Dave bores them for me on a really accurate milling machine – we get them to tenths of a mil. They’re not tight either, they’re just right.”
With sparks provided by a Lucas 2M TT magneto with 34.5º advance – there are no lights fitted, which is okay in the UK if the vehicle is only ridden in daylight hours – the Fredder’s engine produces a very healthy 55bhp at the rear wheel at 8000rpm on UK Dynojet importer Frank Wrathall’s dyno literally just up the road from the Walmsley workshop. That’s helped by the fact that Fred’s longstroke motors use trick race cams, which originally emanated from Reg Dearden’s, the legendary Manchester dealer who often acted as the back door to the Norton factory race shop. “When Dearden finished with racing, a lot of his stuff went to a friend of mine, Eric Biddle,” says Fred. “He had a big collection of Nortons and loads of factory parts that came from Dearden’s, including boxes and boxes of cams. The cam designs and profiles I use came from the stuff that ended up with Eric. They’re experimental Norton cams, but I’ve matched them up and they go very well.”
The high 13:1 compression necessitates running the Fredder on a blend of Avgas and super unleaded, same as on his race bikes. Walmsley runs a 13⁄8 inch (35mm) Amal GP2 carb on the Fredder with a pair of SU remote float chambers, preferring the smaller carb over the 1½ inch items on his race engines on the grounds of rideability for road use. But the choice of twin SU float chambers is mainly aesthetic. “The carb manifold is from my Cooper car,” he admits. “I think it just looks nice, with the big works Norton bellmouth fitted, and a float chamber on either side like we had on the car to counter centrifugal cornering forces. But I have petrol only in one of them, to be honest – there’s two just to look good!”
Walmsley plans to take the Fredder racing this year by fronting up to a ‘run what you brung’ straight line sprint meeting with it in the back of his Chevy pickup, hoping to break the 130mph mark the bike is presently geared for on the road.
The Fredder’s transmission comes courtesy of a five-speed Mick Hemmings gearbox with belt primary drive, combined with a dry Speedway-style NEB clutch and a kickstart – although with that high a compression, you’re better off with a run-and-bump classic-era racing start despite the compression release lever that Fred has fitted to facilitate starting.
But he plans to fit an electric start shortly, sourced via French Vincent guru Patrick Godet who’s already converted most of the V-twins he supplies to electric start. That will entail fitting a battery and an alternator, thus depriving the Fredder of its stripped-down simplicity. Still, he can then fit lights for when he’s caught out late riding home after dark…
Coax the Fredder into life from cold, and you’re rewarded with a fabulous crack from the megaphone exhaust, even though it’s fitted with a nominal DB-killer which doesn’t, however, seem to make much difference! It won’t idle until the engine is really hot – so you must perforce blipping the light-action throttle to warm it up. Heaven! That very trick exhaust is pretty divine, too, comprising a full titanium pipe made by another of Fred’s local Preston mates. Ben Sargeant Fabrications works for nearby Paul Bird Motorsport in repairing all the crash damage on the factory Ducati with which Shakey Byrne won the 2017 British Superbike championship. So when the Panigale racer comes in for the exhaust to be fixed after Shakey’s crashed it, Ben saves all the scrap metal – so the Fredder’s exhaust is actually made from the offcuts of Shakey’s Superbike!
But the actual design of the pipe is down to Walmsley: “I worked out the dimensions and the shape of the megaphone, based on the one on the longstroke Norton I developed which won the 2016 Goodwood Revival, and which has the same cams in it as the Fredder,” he says. “Ben’s father is a silversmith, and he’s excellent at shaping metal to make stuff. He’ll make a cup to go over the reverse cone to silence it a bit more, but we need Shakey to crash again so we can finish it off in titanium!” Ben Sargeant himself also produced the 12 litre alloy fuel tank, and the oil tank side-mounted on the right.
That 55bhp output is pretty tidy, and is actually slightly more powerful than the longstroke 79 x 100mm engine in Walmsley’s 1953 Featherbed Norton that TT maestro John McGuinness and Classic ace Glen English rode to victory for him in the 2016 Goodwood Revival. This made 53bhp on the back wheel at 6500rpm, whereas the Fredder’s engine peaks at 8000 revs with 2bhp more on tap – more than the later short-stroke Manx Nortons built up to 1962 made, as delivered. “The 86 x 86 mm ‘square’ Manxes didn’t usually rev as high as that,” says Fred. “They only went to 7200rpm because of the cams and exhaust Norton used. But they will rev higher reliably, as we do today, for quite a bit extra power.”
The completed engine is installed in the ex-police Model 19 Norton’s rigid frame that’s devoid of rear suspension, after its cradle was cut out and repositioned, and the front downtube bent forward for extra clearance. A set of custom engine plates completes the installation, after Fred took a photo of the frame with the engine fitted, printed it on A4 paper and then sketched in the tanks for Ben to make. “I always wanted it to be a rigid bike, so as to be more authentic,” explains Fred, “because I remember as a kid in the late 1950s and 60s the bobbers were all rigid back then. Triumph does a Bobber nowadays which looks rigid but isn’t, but I didn’t want to go down that street – I just wanted to keep it as it really was.”
But why a 21 inch front wheel, Fred – especially since the choice of performance tyres is pretty limited? The Fredder carries a skinny 3.00 x 21 Avon Speedmaster Mk.II up front, matched to a slightly chunkier 4.00 x 19 Heidenau at the rear. “Basically, it’s for looks,” admits Fred, “but also to find a bit more ground clearance with the Manx engine sitting so low in the chassis, because it’s such a tall unit to squeeze in under the top frame tube. Weight distribution is the main thing on a special, and a lot of people overlook it, so then when they ride the bike after it’s complete, it won’t handle.
“I’ve been really fortunate – you know that phrase about standing on the shoulders of giants? Well, I’ve done that, because Barry Sheene taught me a lot about weight distribution, and some of the stuff he taught is actually in this bike. Barry raced my Manx with a four-kilo weight ballast on the front down tubes, whereas everyone else was trying to take weight off. I made sure the Fredder’s engine was in the right place at the stage we were modifying the Model 19 frame to suit the twincam motor, so thanks to Barry I reckon it handles okay. What did you think of it?”
Well, I actually had two chances at answering that question, after the Fredder made its public debut last June at the Goodwood Festival of Speed, where Fred used it as paddock transport. Pitted right next door to Team Walmsley in the Paddock, I couldn’t resist his invitation to give his creation a run on the Hill, and riding it down to the start gave me a strong clue I was going to enjoy this – it had brisk acceleration from low down as shown on the separate speedo and rev-counter sitting in the face of the fuel tank, in best Transatlantic style.
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