Nearly four months after the introduction of Ferrari’s most important update in the 2025 the Formula 1 season, new insights have emerged regarding Ferrari’s rear pull-rod suspension on the SF-25. These behind-the-scenes details reveal the doubts within the Maranello team, who had initially developed a flawed and misleading design. The upgrade introduced at the Belgian Grand Prix was never expected to revive the season. Let’s explore what really happened.
Ride height issues: the SF-25’s fundamental problem
Even before the car hit the track, Ferrari’s team led by Loic Serra identified problems on dynamic rigs that simulate real-world driving conditions, including track irregularities and camber angles. These issues were confirmed during pre-season testing in Bahrain, where rear-end handling proved deficient.
This translated into a core weakness of the SF-25: it often could not operate at its intended ride heights, losing crucial aerodynamic performance. The Chinese Grand Prix highlighted that the car could not lower its floor too much without damaging the plank, the wooden panel under the car used by the FIA to measure skid block wear.
FIA regulations limit wear to a maximum of 1mm at four specific points along the plank during a Grand Prix. All teams operate close to this limit over 300 kilometers to maximize aerodynamic performance. The precision required to balance this is extremely high.
Teams like McLaren and Red Bull successfully managed this critical component, shifting plank wear toward the front to protect weaker points and reduce degradation in sensitive areas. Ferrari, however, failed to manage this, as they could not shift maximum wear toward the front of the car.
SF-25: what Ferrari aimed to achieve with the rear pull-rod update
To address this, Ferrari decided to halt all other upgrades and focus on resolving this technical challenge. In hindsight, this decision, announced by Frederic Vasseur at the time, was not particularly forward-thinking. Ferrari began studying the car’s dynamics to try to correct the issue.
The goal was to modify the rear kinematics to stabilize the aerodynamic platform under specific driving conditions. Changes targeted the upper control arm, with attachment points moved vertically and longitudinally, lengthening the first link. This increased the anti-lift function of the suspension.
The objective was to reduce rear compression under braking, when the car naturally lifts at the back. This involves delicate compromises: increasing anti-lift can reduce the suspension’s ability to resist squat, meaning prioritizing one behavior changes how the platform reacts in different dynamic scenarios.
Did the update solve the SF-25’s problems? Not at all. The upgrade expanded the car’s operating window, giving engineers more flexibility for setup adjustments, but the car’s fundamental flaws remained. This brings us back to June, when delays in the rear suspension were first discussed.
Ferrari suspension: nearly €3 million for a largely ineffective modification
By July 4, reports indicated that the rear suspension had been ready for over a month, but tests to verify its effectiveness had failed. More study was needed before track deployment, delaying its installation. Further testing at Mugello aimed to gather additional data.
Internal sources revealed the financial cost of the upgrade: over €2.5 million, a significant investment in a season already compromised. The suspension itself was not radically altered, yet this expense affected Ferrari’s budget cap, limiting other upgrades. Ultimately, the money spent did not deliver the expected results.
Another crucial factor is that before manufacturing the update, the rear pull-rod modifications were rigorously tested on simulators by three Ferrari drivers, with one leading the data collection effort.
Ferrari knew the update wouldn’t solve the SF-25’s problems
After two days of intensive simulator testing, the lead driver strongly advised against investing in this upgrade, as it clearly did not resolve the car’s issues. Despite this warning, Ferrari built the components and conducted “seven post rig” tests in early July, which failed to convince the team and further delayed the schedule.
In summary, the upgrade was not entirely useless: it provided a slightly wider setup window, helping drivers and engineers optimize aero-mechanical compromise for each Grand Prix. However, the original objective was not achieved. Ride height issues persisted, and the rear end never functioned as intended. Testing was justified, as sometimes only track conditions reveal the true effectiveness of an upgrade—but in this case, it was not successful.
