Rumors suggesting that Ferrari will implement a technical shift for its 2025 F1 car, moving from a front suspension with a “push rod” setup to a “pull rod,” are growing increasingly persistent. Such a choice would represent a significant change in the car’s mechanics, with repercussions for aerodynamics and weight distribution as well. Let’s analyze these configurations.
Comparison of Configurations
In the “push rod” configuration, the arm connecting the wheel hub to the elastic components mounted on the chassis slopes upward. In other words, the component is attached “higher” on the chassis side than on the wheel side. Consequently, during relative movement where the wheel is raised relative to the chassis—such as when passing over a bump or curb or during cornering roll and vehicle pitching—the arm compresses the elastic components. Thus, it is called a “push rod” because it works under compressive stress. This has been the configuration chosen for Ferrari’s front axle until the past season.
The “pull rod” suspension Ferrari may adopt, on the other hand, is the exact opposite. The arm “descends” from the wheel hub to the elastic components, which are positioned much lower on the chassis. In this way, the arm comes into action by “pulling” them. It works under tensile stress, which is why it is referred to as a “pull rod.”
What Are the Pros and Cons?
First and foremost, the effectiveness of a suspension is determined by how well its kinematics transmit wheel movements to the chassis—a factor not directly tied to whether it is a push or pull rod but rather to the specific design and its geometry. That said, there are other aspects subject to a global evaluation of these philosophies.
The type of suspension also impacts other areas of the car, such as aerodynamics. Like any component exposed to airflow around the car, it generates drag. Optimizing this aspect, especially in aerodynamically critical areas, greatly enhances the car’s efficiency. This benefit becomes particularly significant in high-speed sections. In this context, both the placement of the arm, based on its inclination, and its size must be considered. As previously noted, push rod and pull rod arms are subjected to different stresses and have varying lengths. Consequently, during the design phase, they are sized differently, resulting in distinct cross-sections. In this regard, pull rod suspension tends to be more advantageous.
Regarding weight distribution, the pull rod configuration is superior. By placing the elastic components lower than the alternative, it allows for a lower center of mass. However, this configuration may be less accessible during assembly or adjustments. In a racing situation, where timing is critical, this could make push rod suspension more advantageous.
In conclusion, as evident, while each configuration has its peculiarities, no option outright dominates the other. Much depends on the design choices made by engineers to optimize various performance areas. It remains to be seen whether Ferrari will indeed adopt the much-discussed pull rod front suspension when the new car is unveiled.
Source: f1ingenerale
Leave a Reply