The Evolution of Rear Suspension in Formula 1
Mercedes has made a significant decision to abandon its rear suspension package, which had been intermittently used on its Formula 1 car since its debut at the Imola Grand Prix. Although the package was not directly blamed for the team’s performance issues, it was seen as an obstacle in refining and understanding the W16 chassis further.
The primary objective of the suspension package was to reduce rear axle lift under load. The idea was that by maintaining a more stable downward force on the rear tyres, the underbody could remain at a consistent level, thereby generating a steady amount of downforce. This concept was implemented at Imola, then removed at Barcelona and Monaco, and reintroduced at Montreal. It was during the Canadian race that Mercedes secured its first (and only) victory of the season, thanks to George Russell's impressive performance.
Andrew Shovlin, Mercedes' trackside engineering director, noted that the conditions in Montreal masked some of the stability issues that have become evident in recent races. This delay in recognizing the problems prolonged the decision to permanently remove the package, which finally happened at the Hungaroring.
Other teams, including Ferrari and McLaren, have opted for suspension packages with clear anti-lift properties. Shovlin explained that designing a rear suspension package in conjunction with a new gearbox is inherently a compromise. This challenge is even greater when developing a new package for an existing gearbox design, especially under the constraints of the cost cap.
"The reality is even if you're designing a suspension and gearbox with a completely blank sheet of paper, it is an enormous compromise between where the aerodynamicists want to put all the legs, the various compliances, the kinematic characteristics, where the roll centres are... and it is impossible to actually set everything exactly where you want it to be," Shovlin explained.
"So the whole thing is a compromise, and that compromise is more extreme when you're doing it to an existing gearbox and an existing suspension – and the cost cap means that you can't just rip it all up and start again. The compromises that we might have faced could have been very different to those that Ferrari or McLaren had, so it's definitely getting into the subtle detail. McLaren have clearly made a great success of it, but it's not difficult to see how certain aspects can catch you out."
In previous eras of Formula 1, suspension layouts were largely fixed. Teams typically used a push-rod front suspension and pull-rod rear layout. While some later designs allowed for minor adjustments at higher steering angles, these were relatively small modifications to an otherwise conventional setup.
The introduction of ground-effect floors has changed the landscape. These floors require consistent ride heights to function effectively across different cornering conditions. Even in the 1981 Lotus 88, which was a primitive example by modern standards, the importance of maintaining Venturi tunnels at a stable level was recognized. The twin-chassis design featured a softly sprung inner chassis and a stiffly sprung outer chassis to ensure the ground-effect floor maintained a consistent height.
Contemporary anti-lift rear suspension systems operate on a similar principle, aiming to keep the floor at a static ride height. At this stage, the aerodynamic gains from the floor are marginal, prompting teams to explore the kinematics involved to maximize performance.
Shovlin also highlighted the influence of external factors on the decision to delve deeper into suspension development. With the upcoming 2026 cars, teams are eager to utilize their wind tunnel allowances. "I think it's the extent of how far you push it," he said, "not so much that lots of teams may well have had a percentage of anti-lift in the car, but what you could see that McLaren were doing was pushing that extremely hard."
As aerodynamic gains from regulations begin to diminish, teams are looking for smaller performance steps. Additionally, the need to shift wind tunnels to next year's regulations naturally leads teams to explore areas they may not have previously considered. From a vehicle dynamics perspective, it makes sense to focus on these areas as aerodynamic development starts to plateau.