Motorcycle.com

Back in the day, long before I was but a glimmer in my parents’ eyes, single-cylinder motorcycles ruled the roost when it came to road racing. If you wanted to go fast or be top dog, then you hopped on a Single. Any number of manufacturers were building them because popping out one cylinder was much easier than pumping out multi-cylindered machines, but the early history of road racing belonged to British Singles.

In this Top 10, we celebrate one-lunged racing machines with an assortment of models. Britain, clearly, has the most representation on this list, but other locales that have contributed to racing make an appearance, too. Yes, we realize Singles are alive and well in off-road racing, but for the purposes of this list we’re going to stick with blacktop. With that, here we go.

Britain might be known for its Singles history, but Germany has its own rich history racing Singles. In 1955 the 250cc Sportmax models, in particular, were popular with privateers, as NSU had decided it was pulling out its factory effort the year before and ended up selling bikes and parts to anybody with the cash for the ’55 season. Consequently, the bikes were also popular in racing circles, able to keep up, and sometimes defeat, twin-cylinder machinery. The highpoint for the Sportmax came in 1955, when Hermann-Paul Müller took one all the way to the 250cc crown – one of the rare instances where a true privateer has won a world title. As for the bike, the 247cc four-stroke was rated at around 30 hp somewhere north of 9,000 rpm. Sportmax examples (some authentic, but mostly replicas) still pop up at vintage races and on the auction block from time to time, with and without the dustbin fairing.

Today we revere MV Agusta for its high-horsepower, multi-cylindered motorcycles, but the company’s early days were centered on single-cylinder motorcycles. Its two-stroke versions from the late 1940s were successful items, winning road races into the early 1950s, but were outgunned by four-strokes at the world championship level. Count Agusta countered by hiring the best minds of the time to build a winning motorcycle. The Bialbero was it, and it won the 1952 125cc title in the hands of Cecil Sandford, though some would argue that title is hollow due to the dominant Mondial team withdrawing from competition that year. Nonetheless, the record books will forever show that MV Agusta won its first world championship (of 37) that year, and added five more by the end of 1960. MV’s success in the premier 500cc class would come in 1956 in the hands of John Surtees – to this day, the only man to win titles at the highest level of both motorcycle (500cc) and car (Formula 1) racing.

Velocette’s reputation has always been about high quality and forward thinking. The bikes were light, handled well, and in the case of the mkVII KTT models, extremely rare as only 39 bikes were produced. In fact, the picture above is a mkVIII, but there are many similarities. The K engines in the KTT series are 350cc with overhead cams – a very advanced feature for the 1930s. Racing success wasn’t immediate due to handling issues, but factory rider Stanley Woods suggested moving the engine further forward in the frame, and the Oleo Strut company fabbed up some shock absorbers to attach to the swingarm, creating the birth of modern rear suspension – in 1938! Soon enough the bikes were doing well at the Isle of Man TT. So much so that Woods won the Junior TT that year and came second in the Senior race.

With the AJS 7R, the British company was returning to post-war life the only way it knew how – racing. The 7R debuted in 1948 with a 348cc engine and often punched above its weight, pumping out 30 hp and weighing about 300 lbs, both numbers rather competitive for its day. It was so competitive, in fact, that Les Graham won the Swiss Grand Prix in 1950 aboard one, beating out the likes of Norton and Moto Guzzi. Privateers continued on with the 7R well into the 1960s, where constant development enabled the bike to remain competitive at the national level.

Harley-Davidson is synonymous with V-Twins, but The Motor Company’s early years featured a few Singles as well. Those early years also saw Harley take on the likes of Indian and others at the board-track races which were known to have fierce competition. This 1929 H-D 348cc Peashooter was built to compete in the “slower” 350cc class, but over the years its development made it nearly as quick as the 500cc trackers. As you can see in this picture, the bike doesn’t have brakes and barely has front suspension (rigid rear). The low handlebars make it clear that this bike had one purpose only – racing. The example above is currently housed at the Barber Museum in Alabama.

One of the most famous motorcycles ever produced, the Norton Manx is rich with history. With both 350cc and 500cc versions built, the Manx’s racing pedigree runs deep. Featuring such advancements as telescopic forks and engines with overhead cams (both single and double), the Manx was a competitive machine at the Isle of Man TT. But 1950 saw a significant advancement for the Manx when the Featherbed frame was developed. The new frame was light and gave the Manx a shorter wheelbase for quicker handling, plus it incorporated a swingarm rear suspension that provided a smoother ride and was the impetus behind the chassis’ Featherbed nickname. A shorter-stroke engine for 1953 gave the Manx a higher rev ceiling, but the factory pulled out of Grand Prix racing the following year. However, that didn’t stop numerous tuners to continue developing and racing the bike. Among the Manx’s many claims to fame, in 1969 Godfrey Nash rode one to victory at the Yugoslavian Grand Prix, marking the last time a 500cc race would be won by a single-cylinder machine.

The best looking motorcycle on this list in my opinion, the Mondial 125cc Grand Prix racer was rather advanced for the late 1940s and early 1950s with its dual overhead cams. It made all the other 125s of the era look rather rudimentary in comparison – an impressive feat considering most of Italy’s manufacturing plants were destroyed by the war. It had an undersquare bore and stroke of 53mm x 56.4mm. The bike didn’t finish its first race, but later went on to record world records in the standing start quarter-mile and kilometer categories. Mondial’s serendipitous timing in developing the 125 also coincided with the creation of the Grand Prix world championship in 1949, where it cleaned house in the 125cc category; winning every 125 race in 1949, 1950, and 1951!

The dustbin fairing seen here wasn’t added until 1957, at which point the Mondial featured gear-driven cams (instead of bevel drive) and not only won the 125cc title, but the 250cc title, too. But that was the end for Mondial’s success, as the Italian firm, along with Moto Guzzi and Gilera, ended their factory involvement with Grand Prix racing, as they came to grips with the eternal truth of racing: it’s expensive!

The history behind the name Gold Star deserves sharing: Wal Handley came out of retirement to race BSA’s then-flagship, the Empire Star (a cool name in its own right) at the Brooklands circuit, where he attained an average speed of 107 mph – in 1937 – where he was awarded the Brooklands Gold Star, a highly coveted prize. So impressed were BSA with the accomplishment that its next flagship model bore the name.

With a history like that, Gold Stars had a lot to live up to. BSA didn’t disappoint, as the Gold Star is arguably regarded as the greatest British Single ever produced. What made it so great? The top-of-the-line, 499cc versions used all alloy cylinder barrels and heads, making them extremely light. According to Classic British Motorcycles, the hand-built engines were available with “different compression ratios, cams, carburetors & exhaust systems, and two different cylinder heads, one for the Trials version and the other for everything else.” In this case, “everything else” included touring, motocross, scrambles, and road racing. Improvements to the Gold Star kept coming through to the late 1950s, but by the 1960s the Single just wasn’t keeping up with the more advanced, and multi-cylindered, competition. Production of the Gold Star ceased in 1963.

Bring up Pierre Terblanche in a conversation of motorcyclists, especially Ducatisti, and he’ll probably be reviled for creating the first-generation Multistrada and for what some consider an abomination of a successor to the 916/998, the 999. But don’t forget that Terblanche was also the guy responsible for designing this, the Ducati Supermono, a motorcycle we at MO all lust lovingly after each time we see pictures of it.

For those who only think of V-Twins when they think of Ducati (commence rant about L-Twins…), here’s a brief history lesson. Designed to race in the popular Sound of Singles class, Ducati introduced one of the most highly sophisticated Singles ever created in 1993 and stopped in 1995. In between, only 67 examples were made.

Underneath the Terblanche-penned bodywork lay what was essentially a 888 V-Twin with its rear cylinder removed. Designed by Claudio Domenicali, who is now Ducati’s CEO, it features four valves, 11.8:1 compression, dual overhead cams, desmodromic valve actuation (duh), and a dummy connecting rod to act as a counterbalancer to quell the inherent vibes of a single-cylinder engine. This allowed the 550cc one-lunger to rev to 10,750 rpm without rattling the rider’s teeth loose and shaking off body panels. More importantly, Ducati claims 75 crankshaft horses. If we’re generous and allowing for 15% driveline loss to the rear tire, that’s still in the realm of 63 hp. For comparison, the current KTM 690 Duke and its 690cc Thumper – with 140cc more displacement – put 69.8 hp to the wheel last time we had it on the dyno.

Making the Supermono even more of a weapon on track was its supremely light weight, with Bologna claiming a dry weight of just 260 pounds. The main frame was traditional steel trellis, but nearly everything else was either carbon fiber or magnesium. And since the Supermono was never destined for the street, Terblanche didn’t have to bother incorporating the necessary crap needed for road legality, also shaving weight.

The Supermono may have been short-lived, but it still saw success. In its debut year, 1993, it won the European, Italian, and Swiss Singles championships. Today, it’s one of the most sought after Ducatis around.

It’s easy to look towards the past when it comes to historically significant Singles, as the modern racing landscape has been dominated by multi-cylinder motorcycles for 50-odd years. However, cutting-edge single-cylinder racing is alive and well and it’s happening right now. It’s called Moto3, and while there are three manufacturers currently competing in the 2016 Moto3 championship – KTM, Honda, and Mahindra (well, four, but the Peugeot entry is just a rebadged Mahindra) – the top spot on this list goes to both the Austrian and Japanese manufacturers.

As of this writing, both the Honda NSF250RW and KTM RC250GP have four wins apiece this season, with Indian firm Mahindra capturing the other two; one at Assen with Francesco Bagnaia, the other at Brno with John McPhee riding the Peugeot. As the photo above illustrates, the Honda and KTM have been very evenly matched this year. The manufacturers are understandably hush-hush when it comes to specifics about current racing machines, but we do know all Moto3 bikes are limited to 250cc with dual overhead cams, four valves, a maximum bore of 81mm, and a rev ceiling of 14,000 rpm. KTM houses its Single in its tried-and-true steel trellis frame, while Honda uses an aluminum twin spar. Weight savings comes in the form of magnesium wheels and triple clamps, though bike and rider combined must meet a minimum weight of 326 lbs.

It’s estimated the top Moto3 machines make somewhere in the ballpark of 55 hp – from its 250cc Single – which equals or betters the Singles from half a century ago with twice the displacement. And thanks to their modern engines, transmissions, brakes, tires, suspension, and chassis, today’s Moto3 riders could easily outpace the great Giacomo Agostini, the 500cc champ from 50 years ago, 1966, aboard his booming MV Agusta.