They improved top speed by an astonishing 15% (about 25 km/h), but most drivers hated them. This is the story of comically named "dustbin" type fairings that proliferated in the World Speed Championship until they were banned in 1957.
Since then, there is nothing more to say about this class of fairings. The dimensions and shapes of this component of today's racing motorcycles are very strictly defined in the International Motorcycling Federation’s regulations. But it was not always like this. In the early days of the World Championship, almost all models lacked them, while in the mid-fifties, if you wanted to be a contender for the title, you had to mount a full fairing that even covered the front wheel. These full aluminum fairings gave rise to the English term "dustbin".
The origins
Motorcycle brands had always been very aware of this aerodynamic configuration, since it was the usual system fitted to models destined to break speed records in the 1930s. Gilera actually experimented with full fairings on their first supercharged 500cc four-cylinder. However, they abandoned him when Dorino Serafini won the European Championship in 1939.
After the Second World War, the first to pay attention to aerodynamics were the Italian brands, specifically in the 125 cc category. With mechanicals of only 12 hp, they quickly discovered that dustbin fairings offered them the possibility of increasing maximum performance, which led to a significant increase in the profits obtained in costly engine developments.
Of course, the advantages disappeared in the slower circuits, due to the additional weight that they entailed, the limitations that they offered to the mobility of the pilots and the greater effort that was required from the brakes, as the weight of the front axle was greater in braking. compared to conventional models. But at home, in Monza, the fastest of the World Championship circuits, top speed ruled and it was then that they emerged as the protagonists of their time.
The final landing came in 1950, when Mondial built a 125 special for the classic test on the Milanese circuit. The front wheel was exposed, but it had a dolphin fairing with no less than three openings, while the rear wheel was completely covered by a wrap-around tail. As this silhouette was located at the rear of the rider, on the straights, the bike and rider formed a perfect "egg", with the front wheel as an addition attached to it. With this bike, Gianni Leoni won the race at an average speed of 131.44 km/h. This made other brands pay more attention to the effect of aerodynamics. Moto Guzzi emerged as a leader in this regard, building its own wind tunnel.
Moto Guzzi, pioneer
Surprisingly, this all took place a whole three years before the boom in "dustbin" fairings in competition. Moto Guzzi, Gilera, MV, NSU and all the other firms involved in racing experimented with small fairings that stretched from front to back, around the yoke and under the rider's arms. But the next fundamental step was taken by Moto Guzzi in 1953. Their investment in the wind tunnel began to pay off. That year, the Mandello del Lario brand competed in the 250 and 350 cc categories with single-cylinder motorcycles, and in 500 cc with a revolutionary four-cylinder to replace the already old V-twin. To reduce the frontal area, it had the cylinders in line with the direction of travel, instead of the transverse ones preferred by its rivals Gilera and MV.
The engine was water cooled and fed by injection, with a four-speed gearbox. It could be defined as a true technical boast, to which the brand's engineers added the first full-fledged "dustbin" fairing, a model like never before seen in any of the three categories. The two lower displacement bikes had dolphin fairings similar to those used today, but with a beak that projected above the front wheel, while the 500 cc had a similar fairing, although without said beak. During the season, the aerodynamics of the half-liter model (which had started with a victory in the Hockenheim race, not scoring for the World Cup, driven by Enrico Lorenzetti), was progressively evolved until at the Italian Grand Prix in Monza , in September 1953, they released the first true "dustbin" model that completely covered the front wheel.
It is true that BMW had built a special fairing for Walter Zeller that featured a full fairing plus tail. But while the German factory did it sporadically, Moto Guzzi went to work extensively and in 1954 both the 250 and 350cc racers wore full fairings of this type from the start of the season. Still not the elegant rounded fairings of years later, but rather stubby models, an evolution of the original developed on the 500 four-cylinder at Monza the previous autumn. Surprisingly, Moto Guzzi withdrew it from competition after only one season, mainly due to lateral thrust problems generated by the longitudinal crankshaft, which complicated its handling on twisty circuits.
brands also entered this war, except AJS and Norton (both, at the time, members of the AMC group), who declared that they were not going to use these fairings because they did not interest the owners of their series models. This didn't stop Norton from fitting a curious dolphin fairing on his Ray Amm factory team bikes. It had a long beak that reached past the end of the front wheel. On the other hand, the progress NSU made was obvious. The German firm began in 1954 with a dolphin model that included a pick very similar to that of Guzzi. However, at the Duth TT in July they incorporated a new piece that fully covered the front end. It was a very rudimentary prototype and already in September, at the Italian GP in Monza, it was replaced by a beautiful one-piece aluminum fairing with a large dome and side panels that contained the pilot's arms.
Gilera also followed this technique, although his designs had smaller canopies and the pilot's arms were left exposed to the air. Geoff Duke gave victory to Arcore's firm on his debut at Monza in 1954 at an average of 178.34 km/h, with a record lap at an average of 180.86 km/h. For its part, MV was slower in its evolution in 1954. They tried several formulas, none of them convincing enough against the competition. At the beginning of the year they attached a small dolphin-like structure, then a curious “half dustbin”, like a small upside-down boat that covered the front wheel, but left it in the air when seen from the side.
If you would like to read more about this topic please look for our blog about the golden age of the “dustbin days”.