Aprilia’s MotoGP Aerodynamic Tricks Revealed

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This overlay view shows how the rider and motorcycle interact from an aero standpoint. (Aprilia/)

Given the secrecy surrounding anything that can give an edge in top-level racing, it’s rare to see companies trying to patent the ideas they come up with in the pursuit of success, especially in MotoGP. Why? Because the patent itself explains what it’s doing, giving rivals a chance to understand and replicate the same concepts, and there’s no guarantee that they’ll even be awarded a patent on the idea at the end of the process.

So it’s a surprise to see Aprilia’s parent company, Piaggio, applying for patent protection over an aerodynamic concept of the Aprilia RS-GP racer, which brought Aprilia its first class victory in MotoGP earlier this year. But it’s a welcome one, as it gives unusually detailed insight into why the RS-GP looks the way it does and perhaps how it has achieved its transformed on-track performances.

Additionally, given that patents are usually used to protect commercial ideas, the document could even be an indication that Aprilia is considering applying the same thinking to future consumer models. The RSV4 is already a machine with close ties to Aprilia’s MotoGP project, and it’s not unreasonable to imagine that future generations of that bike will adopt developments learned on the racetrack.

In this view, you can see how the RS-GP’s bellypan partially covers the lower radiator. (Aprilia/)

You only have to look at the Aprilia RS-GP to see that it doesn’t follow the herd in terms of aerodynamics. The bike’s shape and stance are unusual when compared to its rivals. The front end looks high, with a large gap between the front wheel and fairing, and the shapes of the bellypan and side panels are distinctively different. Some may argue that it isn’t pretty, but to a team that’s been trying to achieve GP success at the top level since the 1990s, but failed to achieve the glory it’s experienced in the smaller classes and World Superbike (WSBK), the latest RS-GP is very beautiful indeed.

The new patent applications come from the pen of Marco de Luca, project leader for the RS-GP, and show that despite its protruding nose wings and even a rear spoiler that appeared earlier this year, it generates downforce using the shape of the bellypan rather than simply with those bolt-on parts.

The current bike’s shape has been evolving since a complete redesign was done in 2020, when Aprilia adopted a 90-degree V-4 rather than the previous, narrow-angle design, but it was in 2021 and 2022 that the ideas shown in the new patent documents hit the track.

The idea starts at the front with that large gap between the bike’s nose and front wheel, drawing air in above the tire, around and between the fork legs, to feed the larger of two cooling radiators behind. That upper radiator is pretty conventional, but angled slightly to deflect any excess air downward, toward the lower radiator and the first of the RS-GP’s unusual ideas.

A closer look reveals how airflow around the front wheel/tire and radiators is directed to create downforce. (Aprilia/)

The bottom half of that lower radiator is, unusually, hidden behind a bulb-shaped prow at the front edge of the bellypan. On most rival machines, the radiators are exposed to frontal airflow, but Aprilia instead relies on the flow diverted down from the upper radiator—allowing the opening for the radiators to be only 80 percent of the height it would be if the entire radiator area was exposed. The rounded front area of the bellypan does multiple jobs. Its shape helps control airflow coming both from above, where it’s dropping down behind the front wheel, and the flow coming past the sides of the wheel. But it also acts as a scoop, splitting off half the downward flow and collecting it in a high-pressure area ahead of the lower radiator.

The high-pressure air collected there helps force flow through the radiator, but also creates a pressure differential to the air below the belly, which is being accelerated by the bodywork’s shape. High pressure above and low pressure beneath, means the belly itself is being forced down, pushing the tires into the asphalt.

As air exits the bellypan it is directed up and over the rear wheel/tire, helping to cool the tire in some cases, while also creating rear-end downforce. (Aprilia/)

The innovative thinking doesn’t stop there, either. The Aprilia’s bellypan also differs from its rivals at the back. At the back of their bellies, most MotoGP bikes (and road-going sportbikes) taper to a point, but the RS-GP’s underside sweeps upward, directing air traveling underneath through a gap in the swingarm ahead of the rear tire. A scoop-shaped airfoil attached to the underside of the swingarm helps encourage the air in that direction. Above the swingarm, the rear hugger is kept well away from the rear tire, with its inner surface acting as an extension of the bellypan and channeling air from under the bike up and over the rear wheel.

As well as creating additional downforce, that upswept airflow going over the rear wheel helps keep the tire from overheating. In cold or wet races, where it’s essential to keep the rear tire’s temperature up, the patent shows that an additional, inner fender can be fitted closer to the tire, still allowing the downforce-creating effect of the airflow, but eliminating its cooling effect. That inner fender is adjustable in size, with two close-fitting sections able to slide against each other to manually tailor how much air is hitting the tire.

In wet conditions, when heat is wanted in the rear tire, different mudguards can be used with different spacing to the tire to retain heat. Could this be automated on a future Aprilia streetbike? (Aprilia/)

It’s in this final element that there’s a hint in the Aprilia patent toward a potential streetbike version of the idea. In MotoGP, the bodywork isn’t allowed to move, so that inner mudguard section would have to be manually adjusted in the pits. However, the patent also says that the system could be automated, using a servo to extend or retract the inner fender section. It could be automatic, using tire temperature sensors to decide when and how to adjust its position, or rider controlled. That wouldn’t be allowed in MotoGP, but in WSBK there is a provision that allows for movable bodywork if such equipment is fitted as standard to the homologated streetbike that the racer is based on.

MotoGP is essentially a marketing exercise and the old adage of “win on Sunday, sell on Monday” means it makes sense that the next-generation of RSV4 streetbike will adopt some visual similarities to the RS-GP. If those visual signatures also increase performance, there are unlikely to be many complaints.

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