Aprilia F-duct taking a leaf out of the McLaren playbook

Aprilia appeared at the first MotoGP race of the year in Thailand with quite a surprising update that we have seen before in Formula One.

The manufacturer arrived with an open duct that the rider closes with their elbow to change the aero between high speed or high downforce.

It brings comparisons to McLaren’s F1 F-duct that appeared in 2010.

Switchable Aero

Over the past decade, aerodynamics in MotoGP have switched from low drag streamlining to better downforce.

It’s an inevitability, however, that with downforce comes with drag.

So while downforce is great for speed in the corners, it will always be inefficient, in that it will slow the bike on the straights.

As with F1, the aero teams are seeking to find downforce for corners and low drag for straights.

Unfortunately, conventional designs do not bring both.

Over the decades F1 has played with flexible aero, collapsing suspension, before finally settling on active aero.

Starting with DRS and new for 2026, with straight line and corner modes, where the wings switch between high and low downforce under driver control.

There was one other solution that appeared just before DRS, McLaren’s F-Duct.

This was a complicated duct system. That was used to stall the rear wing on the straights.

As moving aero surfaces were not allowed, it cleverly employed the driver to cover a control duct that switched the system from high-downforce to low-drag.

The Aprilia system is far simpler but uses the same basic method of rider interaction with the aerodynamics.

The Aprilia system in action

The crucial elbow control duct was only seen in first practice for the Thailand grand prix.

It was journalist Simon Patterson that picked up on the design and has helped in guiding this article and illustrations.

Starting from the front, two inlet ducts are obvious on the front fairing, and something that Aprilia have run in the past, albeit for different purposes.

The ducting from these inlets can be seen passing inside the fairing and then protruding upwards by the side of the fuel tank.

It can be seen that the rider is able to close this control duct with his forearm/elbow when on the straights.

When cornering, the rider’s body position is much more open, and the control duct is left open and able to blow along the tail unit.

Given the aerodynamic obstruction the rider presents while manoeuvring themselves over the bike through corners.

This blowing effect from the control duct possibly helps the leg wing and rear wing of the bike work better through corners. Meeting the system’s aim of increasing downforce.

The other effect of the system is to reduce drag on the straights.

A motorbike’s drag is caused by numerous factors but includes the drag from the wings and also the hot air outwashing through the fairing from the radiators.

Most MotoGP bikes have one large primary outlet on the side of the fairing to vent the hot air from the radiator. Aprilia has three smaller outlets.

When the rider’s elbow closes the control duct, the air flow is ducted downwards to three slots aligned with these three hot air outlets.

The air blowing through these 3 slots deters the hot air from the radiators to pass out through them. Instead, passing inside the fairing and out behind the bike, reducing the outwash created corner mode.

By having three smaller outlets rather than one large one, it seems Aprilia is able to manage the drag reduction consistently with the duct system.

A possible side effect of this system in its straight-line closed setup, is that the duct no longer blows the leg wing or rear wing, which could possibly reduce the drag they create.

Although it has to be said that the rider in the tucked in prone position probably has a bigger effect anyway.

Will it stay?

The legality of this system appears to be valid as there are no movable aero parts, except for the rider who cannot be counted in this regard.

This was exactly the same situation in F1 for McLaren.

The FIA were trapped in a loophole they didn’t foresee, so agreed to keep the design for the rest of the season and then ban the system at the season’s end.

It’s likely therefore that the system will remain on the bike and could be copied, as other teams homologate updated bodywork.

But with new regulations coming for 2027, the FIM are likely to ban this innovation anyway.