MotoGP aero bans: we’ve been here before

MotoGP

In MotoGP’s first decade, so-called dustbin fairings were banned because they were too slippery. At the end of next year, MotoGP’s current fairings will be banned because they generate too much downforce by being too draggy

1956 Moto Guzzi 500cc V8 motorbike

Before MotoGP rules became restrictive – Moto Guzzi’s glorious 500cc V8 MotoGP bike of 1956, the year before so-called dustbin fairings were banned

Moto Guzzi

Author

Mat Oxley

MotoGP aerodynamics have been one of the most controversial aspects of the championship for the last decade, since Gigi ‘Gadget’ Dall’Igna started the first serious work on downforce aero in 2015 and 2016.

First it was winglets, then it was enclosed wings, swingarm winglets, seat wings, ground-effect diffusers, ground-effect bodywork bulges and swingarm wings.

The usual formula is this: convert horsepower and drag into grip.

Downforce aero makes race bikes faster, because it adds load to the tyres which improves grip and turning, it adds load to the front end which improves braking stability, it reduces wheelies which increases accelerations and so on.

It also spoils the racing, by making overtaking more difficult, which is why many fans scream, ‘Ban the lot!’

That will most likely never happen, but MotoGP’s current aero will be banned from the end of next year and replaced by lower downforce bodywork, which should put less load into the bikes and tyres. The aim (the hope!) is that reduced downforce will allow riders to overtake more easily, thereby improving the quality of the racing.

Fully enveloping fairings made the bikes very difficult to handle

MotoGP has been here before.

The first MotoGP bikes of the late 1940s and early 1950s were naked. Zero bodywork. As speeds increased and competition got tighter, engineers looked for ways of increasing speeds via reducing drag.

In other words, early MotoGP aerodynamics work was the opposite of today’s. The idea was to smooth the airflow around the motorcycle to reduce drag, rather than using the drag to increase grip.

Moto Guzzi motorbike in wind tunnel

In 1950 Moto Guzzi became the first motorcycle manufacturer with its own wind tunnel, which allowed it to lead the MotoGP aero race

Moto Guzzi

Italian manufacturer Moto Guzzi led the way, because in 1950 it became the first motorcycle company with its own full-size wind tunnel. In 1953 Guzzi produced the first full-enclosure fairings, which were soon nicknamed dustbins.

When Guzzi’s engineering genius Giulio Cesare Carcano wasn’t busy designing motorcycle fairings in his wind tunnel, he created the two-man bobsleigh that won the gold medal in the 1956 Winter Olympics.

Some people hated the look of the dustbins, just like some people hate the look of today’s MotoGP aero, but the boost to performance was considerable, especially because race circuits back then were much faster than today’s circuits. And the faster you go the greater the air resistance, so the greater the need to reduce drag.

From the archive

When Geoff Duke won the 1955 Italian Grand Prix at Italy’s Monza, his race speed was 113.7mph, aboard a 65-horsepower, 150mph dust-binned Gilera 500cc four.

Today’s fastest MotoGP circuit is Australia’s Phillip Island, where last year’s winner Marc Márquez averaged 112.7mph, aboard a 300-horsepower, 225mph 1000c Ducati Desmosedici.

Very soon all the manufacturers were fitting dustbins to their MotoGP bikes. The technology reached its peak with Carcano’s glorious Moto Guzzi V8 500, which wore a fabulously expensive fairing fabricated in magnesium.

The V8’s fairing always raced with its fairing painted a muddy green. In fact this wasn’t paint, the colour came from chemical treatment to prevent the magnesium corroding.

Very soon there were all kinds of people complaining about dustbin fairings.

By the way, the V8’s eight 62.5cc cylinders disprove the common belief that the Japanese manufacturers were the first to miniaturise cylinder size to increase revs and therefore power, a decade before Honda’s 250cc six.

Very soon there were all kinds of people complaining about dustbin fairings.

First, there were safety concerns, because these fully enveloping fairings made the bikes very difficult to handle, especially in sidewinds. Then there were the manufacturers that disagreed with this new avenue of development. These included Norton, which quit MotoGP at the end of 1954, its 500cc single still equipped with nothing more than a tiny flyscreen. And finally the governing body, the FIM, was concerned that hiding the riders from view was bad for spectators.

1953 Moto Guzzi 500cc motorbike

Guzzi’s very technically advanced longitudinal four-cylinder 500cc MotoGP bike of 1953 – its fairing was similar to the so-called dolphins that replaced the dustbins

Moto Guzzi

Therefore dustbins were banned at the FIM congress of October 1954, when Count Giovanni ‘Johnny’ Lurani Cernuschi, president of the FIM’s sporting commission, came up with this formula, which has remained largely unchanged since.

“Nothing should exceed the vertical plane running through the axis of the front or rear wheel; the whole of the front wheel should be visible, the rider should be completely visible from every angle, except the front.”

When the dustbins were thrown out, they were immediately replaced by so-called dolphin fairings, basically similar to today’s bodywork.

In fact Guzzi’s Carcano had already started down this road with his beautiful 1953 longitudinal four-cylinder 500 – four cylinders in tandem, not side by side – which had a more minimal fairing, with front fender. This machine was very technically advanced, with shaft drive, linked brakes and an early type of fuel injection.

Since then MotoGP’s aero rules have been tweaked as motorcycles evolved. For example, as front geometry steepened – in search of quicker steering – fairings were allowed to protrude beyond the front-wheel axle to increase stability.

The 2027 aero rules should decrease aerodynamic downforce by shrinking the size and shape of the upper front fairing, where most downforce is generated. The maximum width of the upper fairing reduces by 50mm to 550mm, the fairing nose is moved back by 50mm, the maximum height at the rear of the bike is reduced by 100mm to 1150mm and the rearward taper of the front fairing aero appendices are narrowed.

The most important measurements here are the upper width and the fairing nose, because moving the nose back should significantly reduce the load over the front tyre. These reductions should also reduce the wake effect, though we won’t know by how much until the new bikes – which will also feature smaller 850cc engines and no ride-height devices – are actually racing in 2027.

Comments

Loading Comments