Over the years in MotoGP we have seen some particular fairings, which however have not worked for various reasons. Let's see them closely.
Since aerodynamic appendages made their appearance in MotoGP in 2015, we've seen many different models and styles. These include fairings that favor high aerodynamic support, but which have had little success.
The objective of this type of fairing is to increase the support surface to reduce wheeling. But it is this force that creates problems in other areas. In fact, this can make the bike extremely heavy at the front, upsetting its balance. Downforce can lead to understeer and make it difficult to change direction. Consequently on some tracks these fairings don't work.
Aerodynamics versus handling
With regard to this type of fairing, the pilots have declared that it has considerably reduced wheeling. In fact, it provides much more support than the previous one, for several reasons. The first is that the upper aerodynamic element is sufficiently spaced from the lower one.
To create downforce, air circulating around a fin produces high pressure above it and low pressure below it. The separation of these two air densities creates downforce. If the elements that make up the flap are too close together, the air streams will eventually mix. Thus they form a vortex and reduce the support force created (here the in-depth analysis on the fins).
Second, this fairing creates a high lift force due to its surface area and angle of attack. The former is relatively large and the latter is high enough to help lift the vortex. This fairing was efficient in terms of downforce, but also had disadvantages.
One of them was related to curves. In MotoGP, aerodynamics are extremely complicated. The center of gravity and the angle of the bike are constantly changing, consequently also the level of support.
When the bike is at high lean angles, the aerodynamic fairing creates less support. The weight in the front helps the rider have better feel and greater cornering ability. Excessive weight, however, can 'push' the bike away and create understeer. In our case, this particular aero fairing wasn't ideal when cornering.
Marc Márquez had stated that the balance of the bike was not optimal with this fairing. As a result, it would have been difficult to keep fast for the entire race distance.
A very interesting comment because, just over a year later, Ducati unveils the "spoon", the small fin we see under the swingarm. This appendage creates downforce which helps balance the bike. At high speeds, fairings with a high aerodynamic load lead the bike to widen the trajectory, with difficulty in changing direction. This spoon would redirect some weight to the rear of the motorcycle, reducing the lift force on the front tire. The bike would thus find its balance.
Honda returns to the 2019 aeropack?
In testing at Sepang in 2020, Honda seemed to have chosen this aerodynamic fairing for the new RC213V. It is possible that it is an evolution from what we saw in 2018, because it is very reminiscent of it. The space between the upper and lower spoiler elements is smaller. Which suggests it may create slightly less support than the 2018 fairing, making it more maneuverable when cornering.
After the Sepang test, Honda seemed satisfied with this fairing and wanted to test its operation in Qatar as well. Unfortunately it wasn't that effective, in fact they encountered many problems. Losail, a fast circuit with many high-speed direction changes, was a challenge for this aerodynamic fairing. Unlike Sepang, which has fewer changes of direction.
After testing many different setups, Honda found the 2020 fairing to be the cause of the vast majority of their problems. This brings us back to the 2019 package.
As with many aerodynamic elements, Ducati was the first to try different solutions. During the tests in Qatar in 2017 (in the photo), the Borgo Panigale team presented its "Hammerhead" fairing (the name because it is considered similar to the head of a hammerhead shark). The team admitted that the support was so high that the bike gained almost 10km/h in a straight line compared to the conventional fairing!
Ducati had declared its intention to use this type on slower circuits, where strong acceleration out of corners in first and second gear was required. She hasn't actually been seen on the track since.