More Aprilia Aero Secrets Explained

Admin · January 12, 2024

Aprilia and its RS-GP have been at the forefront of aerodynamic technology for the past few seasons. (MotoGP/)

The battle for aerodynamic supremacy in MotoGP over the last couple of years has led to an astounding array of “growths” sprouting from the world’s most exotic racebikes. Inevitably they’re rapidly filtering down to road-going models looking for either an aero advantage of their own or simply marketing the latest trends. Now Aprilia has filed the latest in a series of patent applications related to its own aerodynamic developments with a new document explaining how the company is pursuing F1-style ground effects in corners.

It’s relatively unusual to see details of racebikes appear in patent documents. The very purpose of a patent is to ensure the inventor is granted the exclusive right to prevent others from using the same idea for their own commercial gain. In the words of the World Intellectual Property Organization, “patent protection means the invention cannot be commercially made, used, distributed, imported, or sold by others without the patent owner’s consent.”

Aerodynamics are now where advantages can be clawed out. Aprilia has been an innovator in this department. (MotoGP/)

That makes absolute sense in the cut-and-thrust world of the showroom business, but not in the sport of racing, where the concept of a level playing field is essential. Arguably, any rival using a patented idea wouldn’t be doing so “commercially” if it’s on a prototype racer. Additionally, it’s certain that racing’s rule-makers would stamp out any attempt from one team or factory to bake in a competitive advantage by using patents. The implication, of course, is that by filing patents for the aerodynamic concepts used on its MotoGP bikes, Aprilia is indicating an intention to use the same ideas commercially (i.e., on production models) at some stage in the future.

Related: Aprilia Patents Aerodynamic Leathers

In a straight line, the Aprilia’s fairings don’t create additional drag, but once leaned over it starts to interact with the ground creating a venturi that helps improve midcorner grip. (Aprilia/)

We’ve already seen patent applications from the company explaining how the RS-GP gets downforce in a straight line and revealing the true purpose of the rear spoiler that’s been attached to more recent versions of the bike. The latest in the series of patent filings takes a look at the ground-effect fairing design that Aprilia pioneered in 2022, with several rivals copying the idea during the 2023 season.

The idea of ground effect is well known, having been exploited in racing cars since the 1970s. It essentially involves creating an inverted wing-shaped profile in the underside of the bodywork and running it parallel to the ground to create a venturi effect, sucking the vehicle downward much more strongly than the wing profile alone would.

The RS-GP’s bodywork features ground effects that begin pulling the bike down to the ground with load once the bike passes 60 degrees of lean. (Aprilia/)

To get the same effect on a motorcycle, Aprilia added wing-profiled, convex extensions to the fairing sides. When the bike reaches a lean angle of around 60 degrees, the fairing side that’s closer to the ground creates a narrow channel between the bodywork and track surface for the air to pass through. That gap expands further back, thanks to the convex, winglike shape of the fairing surface, to create the all-important venturi and generate a low-pressure zone under the bike as the airflow accelerates through it.

The RS-GP’s side fairings are convex with a winglike surface that creates the venturi. (Aprilia/)

Although the ground-effect idea is harder to implement on a motorcycle than on a car, the fact that it’s the fairing’s interaction with the track surface that creates the ground effect means it’s possible to create downforce in corners, when it’s needed the most, but not on the straights where it would introduce unnecessary drag. As Aprilia’s patent document explains: “Obviously, the greater force that attracts the motorcycle to the ground, the greater centrifugal force the motorcycle can withstand without losing grip. This allows taking corners at higher speeds.”

“The greater force that attracts the motorcycle to the ground, the greater centrifugal force the motorcycle can withstand without losing grip.” (MotoGP/)

Aprilia isn’t the first to try to exploit ground effects on motorcycles. Back in 1995 Honda filed a patent for a bike that attempted something similar, but instead of using bulbous extensions on the fairings to create a broader surface running parallel with the ground, it used vanes intended to seal a smaller ground-effect section of the fairing against the ground when the bike was leaned over. Aprilia mentions this design in its own patent application, pointing out that those vanes would rub against the ground, causing friction and potentially lifting the bike’s wheels off the surface and causing a crash.

The fact that other MotoGP teams have cribbed the Aprilia style ground-effect fairing suggests there’s a worthwhile gain to be had from the downforce it creates in corners, and Aprilia’s decision to apply for patent protection of the idea substantially adds to the chance that something similar will appear on a commercial model (likely a road-going superbike like the RSV4) at some stage in the future.

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