BSA unit singles owners are a singularly friendly and enthusiastic bunch
BSA started selling its unit-construction single-cylinder bikes 60 years ago. We met up with five owners to find out how well the range has stood the test of time
BSA’S unit-construction single-cylinder range represented a major step forward for what was, following the purchase of the Triumph Engineering Company in 1951, the largest motorcycle manufacturer in western Europe. In the immediate post-war years, BSA had continued to refine and tweak its well-loved pre-unit models. At the top of the single-cylinder tree was the iconic Gold Star, while for the ride-to-work market there was the frugal C12. But the motorcycling world was changing and BSA’S pre-unit single (and twins, for that matter) were starting to look a little dated. Something new, more modern and versatile was needed. And that something was an all-new, unit-construction single-cylinder machine – the 250cc C15. Announced in late 1958 for the 1959 sales season, the C15 replaced the dated C12. And, while it might have been new, it relied on tried-and-tested technology. The incredible thing was that BSA, over a period of the next 15 years, successfully managed to develop its basic 250cc C15 engine architecture to 350cc, then 441cc and finally 500cc capacities. It’s fair to say that this entire unit singles range enjoyed mixed press over the years – opinions vary, with critics citing poor reliability and lacklustre performance, while others admire the simplicity, ease of maintenance and character of the unit singles.
What’s undeniable is that by 1973, when all BSA production finally ceased, thousands of unit singles had been churned out, in a variety of styles and capacities. So you’d think they must have something going for them. To find out what that certain something might be, we met up with five enthusiastic unit-single owners from the Cheshire section of the BSA Owners’ Club. Having had a sit down and a good chat with them, two things became
‘BSA SUCCESSFULLY MANAGED TO DEVELOP ITS BASIC 250cc C15 ENGINE ARCHITECTURE TO 350cc, 441cc AND FINALLY 500cc’
immediately obvious. Firstly, there’s their genuine commitment to the unit single. And, secondly, there’s a shared preference for riding and enjoying their bikes, rather than getting all obsessive about keeping them in original condition. The guys we met would rather have a bike that works well and lets them get out on the road with their mates than one that looks like it’s just rolled out of Small Heath (or even Meriden). As B50 owner Alex Ledbury says: “Like a lot of guys in the BSA Owners’ Club, I’m not so bothered about originality – I just like riding and the social side of club membership.” THE ORIGINAL C15, which was launched in late 1958 and went into production the following year, sported a pressed-up crank that ran on a ball-race main bearing on the drive side and a bush on the timing side; the big-end was also a plain bush. Alloy pushrods, actuated by a camshaft mounted above the crank on the right-hand side of the engine, operated the overhead valve gear. And although the gearbox was in unit with the engine, it followed conventional BSA practice, with the layshaft running below the mainshaft and a sleeve gear on the left-hand side of the mainshaft. It had alternator electrics and an ignition cam-driven by a shaft (which also drove the oil pump) from a skew gear on the crank.
The rolling chassis of the new model was equally conventional. There was a traditional, lugged and brazed double-cradle-type frame with a bolt-on rear subframe, BSA’S own forks and fairly conservative styling. But, if the C15 was hardly futuristic, it would lay the foundations on which a complete range of new singles would be built.
Scrambles and trials versions of the C15 (the C15S and C15T) joined the line-up later in its launch year of 1959. SIMON MCCARTHY’S C15 is a 1965 model, but runs a 1960 engine. Simon has owned it since 1980, so I guess he must like it. He laughs when I put that to him. “I do. It’s almost part of me. I was 17 when I bought it and it was my only transport. I rode it everywhere for about three years – fitted a rack and panniers, went camping, you name it. Then I bought an A50 and that sort of took over. The C15 stood in various sheds for years until I decided to sort it out – with the help of my 10-year-old son – in 2016. “I’ve done it right. I rebuilt the engine completely, fitting an Alpha timing-side roller-bearing conversion, a roller big-end bearing and Boyer electronic ignition. I resprayed it in the shed, fitted a 120 Watt alternator with a new rotor and I run LED rear lights and a 55/60W headlight, so it’s a practical little bike. I reckon that with the engine
‘THE B40 BECAME THE FIRST SIGN OF AN EXPANDING RANGE BASED ON THE C15’
modifications and the fact that it hardly produces any power, it should keep going forever. I got it back on the road a year ago and I’ve covered about 2000 miles since then without any trouble.” Right now I’m off to add a few more miles to that total. The Ceefer feels incredibly low (thanks to its 17in wheels) and light (thanks to a centre of gravity closer to the ground than a weasel’s belly). The gentlest of swings on the kickstart has the engine chuffing into life, first gear engages without any fuss and I’m away. There’s no point revving the torquey little single hard – I just let the soft power and gentle grunt propel me through the gears. It’s strangely relaxing. The ‘up for up’ gearbox works well and the clutch is as light and smooth as I could wish for. So far so good. The C15 may not be the fastest thing on the road – the bike’s comfortable cruising speed seems to be somewhere between 40 and 50mph – but it’s ideally suited to pottering along the narrow, hedge-lined byways of rural Cheshire. The brakes are easily a match for the gentle performance, there’s plenty of room on the broad dual seat and the sturdy frame keeps everything in line nicely. It perhaps feels a little small for my frame – and definitely looks that way, as you can see from the photograph on the previous pages – but I’m pleasantly surprised at how enjoyable it is to ride. Sometimes you have to adjust your mindset to get the best from a bike – and this is one of them. IN 1961 THE 343cc B40 became the first sign of an expanding range based on the C15. An increase in bore to 79mm gave the extra capacity, but unseen developments included a revised head with narrower valve angle, 7:1 compression and higher gear ratios. More visible were the 18in wheels, seven-inch front brake, barrel with integral pushrod tunnel and a slightly larger fuel tank – but overall, the B40 was instantly recognisable as a development of the 250. A sporting SS80 version of the C15 also appeared in 1961 – probably targeting learner riders following the announcement of a 250cc limit for learner riders. Its claimed 80mph performance was achieved by increases in carb and valve sizes and compression ratio, together with a hotter cam. A roller big-end, forged steel crankshaft flywheels (instead of cast iron) and a primary chain tensioner were aimed at boosting the engine’s durability, while a close-ratio gearbox helped to make the most of the engine’s extra 5bhp.
AFTER SIMON MCCARTHY’S C15, I expected Paul Stafford’s 1968 WD B40 to offer just a little more of the same performance, but I’m in for a surprise. It feels loads torquier than the C15 – and physically much larger. The extra torque is to be expected from the bigger engine, but
the trials gearbox specified for WD bikes really makes a difference, too. The first three ratios are super low, for off-road work, then there’s a big jump to top gear. It takes a bit of getting used to on the road and its comfortable cruising speed is probably only the same as the C15. But it feels completely different to ride, with the Victor-type welded frame and 20in front and 18in rear wheels making the B40 feel like a much larger bike. In many ways, the WD B40 is better specified than the earlier road models. The engine has the more durable roller and ball-race bottom-end and roller big-end – which is why WD B40 engines are in demand for pre-65 trials machines (even though they’re not strictly pre-65). The Victor-type frame is also superior to the old brazed ‘swan-neck’ version. Those ultra-close – and low – first three gear ratios are the only thing that compromises it for road use. That doesn’t seem to bother Paul, though. “I’ve been into bikes all my life,” he explains. “But, about five years ago, I really started to fancy a British bike. I went to look at an AJS Model 31, but it needed a lot of work. This B40 was tucked away at the back of the guy’s garage. He’d started sorting it out, but it needed finishing off. I thought it might be a good thing to do a bit of greenlaning on – and I got it for £800.” That sounds like a bit of a bargain, although Paul has since rebuilt the engine. “It’s been great in five years since then,” he says. “It should have thick control cables, dull chrome on the handlebars and oil tank cap, and a ‘matchbox’ type carburettor, but I’m not too bothered. The Amal Concentric works better anyway. It’s a neat little bike and pretty robust. I’ve ridden it to France, Brighton, Morecambe and Scarborough. Choose the right roads and it’s great.” IN 1962 AN SS90 variant of the B40 joined the line-up – with extra performance gleaned via the same route as the SS80. There had been a few minor changes to the base C15 and B40 models along the way, and the S and T varaiants got a new welded frame for 1963, but the next big change was the adoption of the roller-bearing bigend for the C15 in ’64. There was more to come in 1965, too. The ignition on all models moved from the mushroom-like ‘distributor’ housing on top of the right-hand crankcase, into the timing case. There were a few other minor modifications, too, and the SS80 250 became the C15 Sportsman, but the biggest news that year was
‘THE B44 VICTOR ENDURO HAS THE DROP DEAD GORGEOUS STYLING OF THE ’60S FACTORY MOTOCROSSERS’
the arrival of a new 441cc engine based on the works motocross machines. With increased bore and stroke, the new engine featured stronger crankcases, roller drive and ball timing side main bearings, a chrome-plated bore in an alloy barrel and a stronger gearbox. It was also fitted to a new Victor Grand Prix model – an over the counter motocrosser. There was a street legal version of the new model, too – the Victor Enduro, a detuned Grand Prix engine with a conventional liner in the bore fitted into the welded C15T frame. IAN BURNS’ B44 Victor Enduro promises a similar speed to Paul’s B40, but in a more relaxing manner – and that’s exactly what it delivers. For a bike with the drop dead gorgeous styling of the factory motocrossers of the ’60s, it pulls off the neat trick of making a great road bike – once you’ve got the knack of starting the 9.4:1 compression lump. I can short shift and let the ample torque lug me forward at a decently rapid rate or hang onto the revs a bit longer for an even more dramatic hit of power – all accompanied by a hard-edged crack from the exhaust. Ian says he likes loud bikes. No wonder he’s so fond of this one.
It really is a great all rounder and, while it’s not a bike for motorway cruising, it’s as quick as most things round the back lanes, where the punchy drive out of corners and slim, flickable chassis are just what I want. And just how good looking is it while it’s doing that, by the way?
Very, according to Ian (and me). BSAS are in Ian’s blood. His dad took him to scrambles back in the day and rode a C15-engined, square-frame DOT. Ian was seduced by Japanese bikes for a while, but he never forgot the sight and sound of the booming BSA ’crossers he’d watched in the ’60s. When he helped his dad get a 1950 A7 back on the road a few years ago, the Brit fever took hold again, and when he spotted this Victor for sale by a BSA club member he was smitten. “I bought it and my club run was to the annual club camp,” he recalls. “It was a disaster. Not only had I not perfected the starting drill, but even when I did get it running, it liked to stop rather too often. I read Rupert Ratio’s books about the unit singles and I started to make headway into the problems. I fitted new jets, ensured the carb manifold sealed and went through the electrical system. Eventually, all was good, the bike started and ticked over and I use it every week now. I love it.”
FOR 1966, THE 250s got the stronger Victor crankcases and ball-and-roller main bearings, plus a larger oil pump and the Victor-style gearbox with needle-roller layshaft bearings. More changes were afoot for 1967. The C15 Sportsman was dropped and replaced by a new model – the C25 Barracuda, with a new, square-finned alloy barrel on the Victor crankcases fitted with an all-new crankshaft assembly. The new crank was a one-piece forging, with an alloy conrod with a shell bearing bigend. Compression was raised, a fairly fiery cam fitted and valve adjustment was effected by eccentric spindles. With its glassfibre tanks for fuel and oil, the Barracuda was a sign that BSA were starting to target the sporting rider, rather than commuters, with their single-cylinder machines. The Victor Roadster, launched alongside the Barracuda, was further proof of that, as was the axing of the C15 mid-year. In 1968, the C25 Barracuda became the B25 Starfire and the Victor Roadster, recycling a model name from BSA’S ’50s catalogue, was renamed the Shooting Star, gaining an eight-inch front brake. The Starfire got another boost in compression, to 10:1 for 1969, while the Shooting Star got a tls brake and the enduro version of the Victor became the exportonly Victor Special. But for 1970 there would be more significant changes, with a new, five-model unit singles range announced: two 250s – a ‘Gold Star’ SS (Street Scrambler) and a Victor based on the B25 – and three more based on a full 500cc version of the B44 engine. SO HOW DOES the later incarnation of the unit 250 measure up to the earlier C15? Stephen Edwards’ 1971 B25 provided the answer. An export model that somehow missed the boat back in the early ’70s, it’s a machine that came into Steve’s life by chance. “My wife is a mobile hairdresser,” he explains. “She’d asked me to put her scissors into her bag before she went out to work, but I’d forgotten. She phoned me when she got to her first client and asked me to bring them over. I wasn’t keen on driving all the way there until she told me the gent whose hair she was supposed to be cutting had a bike for sale. I was there in no time.”
That was in 1999, and since then Steve has been sucked ever deeper into the world of old bikes. I’ve got six BSAS,” he confesses. “But this is the one I’d never sell. I’d been out of biking for years until this turned up. It’s what got me back into it. A mate of mine, Ed Wright helped be sort it out. He used to work at BSA on the B50s and Rocket 3s. He knows his stuff. There are a few non-standard parts on it – I did buy an original exhaust for it, but hated it and
‘ON THE ROAD, THE B25 FEELS A WORLD AWAY FROM THE C15 – LOUD, REVVY AND NOTICEABLY QUICKER’
‘THE B50 IS A BLAST TO RIDE, WITH A FAT MIDRANGE AND A SURGE OF TOP-END POWER’