In the highly competitive world of Formula 1 racing, the suspension system of a car represents one of the most crucial technical elements that directly influence its performance on the track. It is not only responsible for absorbing bumps and maintaining tyre contact but also plays a vital role in the car’s aerodynamic efficiency and overall handling characteristics. Across all teams, two main suspension configurations dominate the design choices: the push-rod and the pull-rod systems. Each of these layouts brings its own unique mechanical behaviors, advantages, and disadvantages, which impact everything from structural integrity to airflow management. For the 2025 Formula One season, Ferrari took a daring and ambitious step by fully adopting the pull-rod suspension at both the front and rear of their car, the SF-25. This decision represented a radical overhaul of their previous suspension philosophy, aiming to maximize aerodynamic benefits and reduce the car’s center of gravity. However, despite the theoretical advantages, Ferrari’s bold gamble did not pay off as expected, leading to significant challenges throughout the season.
To fully appreciate the implications of Ferrari’s suspension choices, it’s important to understand the various components that make up a Formula 1 suspension and how they interact. A Formula 1 suspension system is a sophisticated assembly composed of multiple parts working in unison to ensure that the wheels remain in optimal contact with the track surface, while also transmitting forces effectively to the chassis. At the core are the upper and lower control arms, often referred to as wishbones. These are shaped like a “V” or a triangle and connect each wheel to the chassis at two points, allowing vertical movement while controlling lateral and longitudinal motion. Their main function is to maintain the correct alignment of the wheels under dynamic conditions, preventing excessive changes in camber (the tilt of the wheel inward or outward), caster (the steering axis angle), and toe (the direction the wheel points relative to the car’s centerline). Additionally, these control arms absorb the lateral forces generated when the car corners at high speeds, ensuring stability and predictability.
Connected to these control arms is the suspension rod, which in push-rod or pull-rod systems transmits the vertical movements of the wheels to the internal suspension components located inside the chassis. This rod is a critical link that carries the forces from the outer wheel assembly inward, acting as the interface between the wheel’s vertical travel and the car’s internal spring and damper units. The rod’s orientation and mechanical loading differ between push-rod and pull-rod designs, fundamentally influencing how the suspension behaves.
The suspension rod transfers its movement to a rocker, sometimes called a bell crank, which serves as a lever mechanism. This rocker converts the linear motion of the rod into a compressive or tensile force, depending on the system design, which then acts on the spring and damper units housed within the chassis. These internal components are responsible for absorbing the energy from bumps and irregularities in the track surface. The spring compresses to soak up shocks, while the damper (or shock absorber) dissipates kinetic energy as heat to prevent excessive oscillation and maintain tyre contact with the asphalt.
In addition to these mechanical functions, modern Formula 1 suspension components play a vital role in the car’s aerodynamic performance. Engineers carefully design the shape and placement of suspension arms and rods, often covering them with aerodynamic fairings to channel airflow efficiently. This is particularly important in the context of current ground-effect regulations, where maximizing the airflow under the car’s nose and chassis floor is critical for generating downforce. Furthermore, the suspension geometry incorporates features that counteract undesirable body motions during acceleration and braking. The anti-dive geometry resists the front of the car diving under braking forces, preserving aerodynamic balance and improving corner entry precision. Similarly, anti-squat geometry prevents excessive rear-end compression during acceleration, helping maintain traction and stability.
The fundamental difference between push-rod and pull-rod suspension lies in the direction the suspension rod operates relative to the chassis. In a push-rod system, the suspension rod extends from the wheel hub upwards to the chassis. When the wheel encounters a bump or vertical displacement, it pushes the rod upward, which in turn compresses the rocker and activates the spring and damper units. This system has been favored by many teams historically due to its packaging convenience and accessibility. On the other hand, a pull-rod suspension features the rod angled downward from the wheel hub to the chassis. When the wheel moves upwards over a bump, it pulls the rod downward, which activates the rocker mechanism in the opposite direction compared to a push-rod system. While both designs aim to manage vertical wheel travel and maintain tyre contact, their mechanical loading characteristics and aerodynamic implications are quite different.
Each suspension type presents its own set of trade-offs. From an aerodynamic perspective, pull-rod suspension offers distinct advantages by allowing the mass of the suspension components to be positioned lower within the chassis. This lowers the car’s overall center of gravity, which is beneficial for handling and stability. Additionally, by freeing up space in the upper areas of the chassis, pull-rod systems enable smoother airflow beneath the nose of the car, a crucial factor for maximizing the effectiveness of ground-effect aerodynamics under current regulations. Push-rod suspensions, while easier to package above the chassis and more straightforward to maintain, tend to occupy space in the lower regions of the car, potentially disrupting airflow toward the floor and rear diffuser, thus reducing aerodynamic efficiency.
In terms of maintenance, push-rod setups are generally more accessible. Their components are easier to reach in the garage, allowing mechanics to perform quicker inspections, adjustments, or repairs during practice sessions or race weekends. Conversely, pull-rod systems have their components tucked deeper within the chassis, making them more challenging and time-consuming to service, which can be a disadvantage during the fast-paced environment of Formula 1 race weekends.
Structurally, push-rods are subjected mainly to compressive forces during bumps and must be robust enough to resist buckling or flexing under load. Pull-rods experience tension when the wheel compresses the suspension and compression during rebound, requiring extremely precise welding and high-strength materials to maintain reliability. This delicate structural balance makes pull-rod suspensions a challenging engineering endeavor.
In the 2025 Formula 1 season, Ferrari adopted the pull-rod suspension at both the front and rear axles of their SF-25 car, marking a return to a configuration they last used on the front suspension in 2015. This move was intended to bring aerodynamic benefits and lower the center of gravity for improved handling. Other teams varied their approach: Red Bull, McLaren, Racing Bulls, and Sauber combined a front pull-rod with a rear push-rod, a hybrid layout that has proven effective. Aston Martin and Alpine maintained push-rod suspensions at both ends, while Mercedes continued with push-rods front and rear, albeit with aggressive front geometry. Haas retained the Ferrari pull-rod rear suspension but used push-rod at the front for easier development.
Ferrari’s SF-25 was more than just a suspension update, it was a comprehensive redesign of the car’s architecture. The team lengthened the wheelbase, repositioned the cockpit for better driver ergonomics and aerodynamics, reshaped the sidepods, and optimized mass distribution to create a platform capable of challenging rivals such as Red Bull and McLaren on the aerodynamic front. This bold technical risk was driven by the recognition that their previous design had reached its performance ceiling.
The front suspension redesign, led by technical director Loïc Serra, focused on implementing the pull-rod layout to improve airflow under the nose and increase front downforce while enhancing anti-dive properties to maintain stability under heavy braking. The rear pull-rod concept, originally introduced with the SF-24, was refined by Enrico Cardile. Ferrari lowered the gearbox assembly to further optimize rear airflow and boost diffuser performance.
Despite the potential of these innovations, Ferrari’s SF-25 suffered from critical issues. The split responsibility between Serra and Cardile led to a mismatch between the front and rear suspension characteristics. While the front end performed well, the rear suspension structure proved too flexible and prone to torsional flex under load. This lack of rigidity undermined the front suspension’s benefits, creating unpredictable handling and making it difficult to maintain consistent ride heights and tyre performance windows. Drivers found the car difficult to set up, especially on circuits featuring a mix of slow and fast corners, where a stiff yet compliant suspension is necessary.
The instability and unpredictable rear behavior led to compromised tyre management and driver confidence, negatively affecting race performance. Ferrari’s SF-25 was unable to run the stiff setups often required for optimal performance and became unstable when softened to tackle tighter sections, revealing a fundamental flaw in the suspension package.
After months of intensive development, Ferrari is preparing a major rear suspension upgrade, set to debut at the Belgian Grand Prix. This update should feature a strengthened gearbox casing for enhanced torsional stiffness and a revised pull-rod geometry, with the front rod moved forward and the rear rod shortened. This change is designed to distribute suspension loads more evenly, reduce chassis twisting, and improve rear stability and traction.
This mid-season upgrade becomes crucial not only for improving 2025 performance but also for preparing the team for the sweeping aerodynamic and power unit regulation changes planned for 2026. Ferrari views the SF-25 as a development platform to test solutions that will carry over into their next-generation Formula 1 car.
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