Push Rod Suspension

Push rod suspension is a specialized suspension system used in racing cars where a rigid rod pushes against a rocker arm to transfer forces from the wheel to horizontally-mounted springs and shock absorbers located inside the chassis, rather than having these components mounted vertically next to the wheel.

To understand how this works, imagine what happens when a race car hits a bump. In a regular car, the wheel moves up and directly compresses a shock absorber that sits right next to it, standing upright like a pole. In push rod suspension, things work differently. When the wheel moves up, it pushes a stiff metal rod that connects to a lever called a rocker arm. This rocker arm then activates the spring and shock absorber, which lie flat across the car's chassis instead of standing upright.

The system builds on a foundation called double-wishbone suspension, which uses two triangular arms (the wishbones) to connect each wheel to the car's body. The pushrod connects between these wishbones and the rocker mechanism mounted on the chassis. Think of it like a seesaw: the pushrod pushes one end of the rocker, which moves the other end to compress the spring and damper.

Racing teams choose push rod suspension for several important reasons. First, moving the heavy springs and dampers away from the wheels and into the center of the car reduces what engineers call unsprung weight. This means the wheels can respond faster to bumps and maintain better contact with the track surface. Second, relocating these components inboard improves aerodynamics by allowing smoother airflow around the wheels and bodywork, which is crucial for generating downforce in racing.

Another advantage is adjustability. The rocker arm acts like a lever that engineers can fine-tune to change how the suspension responds. They can adjust the ratio to make the suspension softer or stiffer at different points in its travel, giving them precise control over the car's handling characteristics. This level of customization is essential in professional motorsport where fractions of a second matter.

Push rod suspension also helps lower the car's center of gravity by positioning components closer to the ground and toward the center of the chassis. A lower center of gravity reduces body roll during cornering and improves overall stability, allowing drivers to carry more speed through turns.

However, this system isn't perfect. It's more complex and expensive than conventional suspension, requiring additional components like the pushrod and rocker mechanism. Some configurations can actually raise the center of gravity if components must be mounted higher up. Setup changes can also be more difficult since mechanics may need to access parts from underneath the car rather than simply reaching in from the side.

You'll find push rod suspension primarily in Formula 1, where it's been a standard feature for decades, as well as in other high-level open-wheel racing series and GT racing. It's rarely used in regular road cars because the performance benefits don't justify the added cost and complexity for everyday driving. As of 2025, most Formula 1 teams use push rod suspension on at least one end of their cars, with some teams like Mercedes and Aston Martin using it on both front and rear axles.

The opposite of push rod suspension is pull rod suspension, where the rod pulls on the rocker arm instead of pushing it. Both systems achieve similar goals but suit different car designs and packaging requirements.