F1 | Red Bull: “The low chassis makes the front pull effective”

The 2024 season, the third of the current regulatory cycle, has seen other teams switch to the pull rod front suspension, adopting solutions already seen on other single-seaters, in particular Red Bull and McLaren.

The last in chronological order to switch to this scheme were Sauber and Racing Bulls, although the Faenza team shares part of the DNA of the RB19 single-seater, retrieving ideas and concepts that led the Milton Keynes team to be the grid reference. The choice at Sauber was dictated above all by the aerodynamic advantages that the pull rod would guarantee in this specific regulatory set.

The engineers of the Swiss team had already planned the change of scheme well before Key's arrival at the helm of the team, but the technical director himself welcomed this choice, given that he had also adopted it during his career at McLaren. According to Key, the front pull rod would guarantee significant aerodynamic advantages on these ground effect cars, with benefits that outweigh the negative aspects, including the difficulty of access and intervention for adjustments.

Although it was a layout that in the previous regulatory cycle had fallen into disuse since 2016, when Ferrari decided to abandon it in favor of the push rod for the SF16-H, the new generation of cars has allowed us to rediscover that layout also at front end and not just the rear end. The current technical cycle has in fact left room for more combinations at a mechanical level. There are teams that have chosen the pull rod on the front and the push rod on the rear axle, teams that have gone the opposite way, but also teams that have opted for the strut scheme both front and rear.

Red Bull was among those teams that immediately focused on the front pull rod scheme with a decisive choice, which was then maintained in the following two years. The Milton Keynes company is not surprised that other rivals are also approaching this path and has offered some more details on the advantages guaranteed by this solution and why it has come back into vogue after years of absence.

On an aerodynamic level, the tie rod scheme on the front end would guarantee a double benefit on this generation of cars: on the one hand it would guarantee less blockage in the passage of flows, on the other it would allow the dirty trail of the tires in an area to be managed more easily. very sensitive of the single-seater. In fact, until the last generation of cars, engineers tried to manage the flows with bargeboards, which however were substantially eliminated with the introduction of the 2022 regulations. For this reason, the teams had to find other solutions to try to control or reduce turbulence and, according to some engineers, the pull rod would guarantee benefits precisely in this respect.

Red Bull Racing RB20 front suspension

Picture of: Giorgio Piola

“If you consider a push-rod, it is a bulkier suspension element, so it blocks the passage of air more. With a pull-rod suspension, if you can get it to work properly in the lower part of the chassis, you get some advantages, starting with stiffness,” explained Paul Monaghan, Chief Engineer at Red Bull. It is important to keep in mind, in fact, that the new regulations have also limited the teams' possibilities on the use of some elements, such as the interter, which are prohibited in favor of simpler solutions.

Among the reasons that pushed some teams to return to the tie rod scheme again there are also the changes to the chassis desired by the FIA ​​with the new technical cycle. Until the last generation, engineers paid great attention to the flows behind the nose and the front wing, especially with the use of turning vanes or the famous “cloak” to try to manage the air in the most congenial way. On the contrary, from this point of view the 2022 regulations have proven restrictive in that area, seeking maximum cleanliness with much simpler forms.

Furthermore, the chassis height has been revised compared to the previous generation of cars. These elements have made it possible to rethink the suspension elements: “With the new regulation, the height of the chassis is not as high as that of the 2020 and 2021 cars. And if you lower the upper part of the chassis, you also lose the angle with which the push-rod is designed. So, for a given vertical load, the lower the frame, the more load is needed to make the push-rod work.”

Front suspension of the RB20

“So if you can find a better mechanical solution and you can make it work, manage it inside the frame and find an easy way to access it for adjustments, then there is a better way to go, which is the pull rod” , added Monaghan, explaining why the tie rod scheme has returned to being a very valid solution from 2022 onwards. To be able to facilitate the interventions of the mechanics who have to act on the internal mechanisms of the suspension, the engineers also worked on the arrangement of the elements and on the creation of a rather large cockpit from which to access.

“A lot depends on where you choose to fit the push rod strut at the top of the frame, or where you can position the pull rod strut in terms of heights during the development phase. This is a key element, because what you're trying to do is precisely manage the ground clearance at the front and with these cars you don't have a particularly wide working window. So if a suspension is not designed well and the integration into the chassis is not optimized, causing you to lose freedom in terms of ride height adjustments, then performance will be negatively affected.”

“Once you have chosen which scheme to focus on and once you have understood the compromises regarding packaging, it is just a question of how much and how you can integrate it into the frame”.