With the latest mess from Mercedes and its suspension capable of lowering the height of the rear axle of the single-seater in a straight line, the focus has returned to a mechanical aspect that, although it has not had ‘notorious controversies’ in recent years, is still a system fundamental that can tip the balance of a Formula 1 towards victory or defeat. But how do the suspensions of an F1 work?
Street and sport suspension
The first thing is to understand how a street suspension does it, and specifically the sports one (which can be mounted and used without problem in almost any car).
A suspension aims to store and absorb the energy of the impacts of the vehicle in the potholes and unevenness of the asphalt. It consists of two elements: elastic and shock absorbers. The elastics store the energy and the shock absorbers absorb it.
A suspension, without going into extensive details, coil-over style, has a spring , which is responsible for storing the energy of the impacts and returning it vertically between the anchor points. Changes in the number of coils or their stiffness can have drastic effects on the cornering behavior of a car, as well as regulate the height to a certain extent.
The second most important element is the shock absorbers , which are usually hydraulic. They are responsible for controlling the return of energy from the elastic elements (which would produce a rebound effect on the bodywork). This damping effect is achieved by forcing the passage of a fluid (oil, usually) through openings and calibrated ducts that can harden or soften the assembly.
Attached to these two elements are the silentblocks , which blur the movements of the mechanical parts between each other and the chassis. The ball joints allow the steering systems to be attached to the wheels so that they pivot; The stub axle and the hub join the wheels to the different parts of a suspension, among which are also the suspension arms (which join the stub axle and the hub to the vehicle and support the tension of the system) or the stabilizer bars (whose stiffness contributes to eliminate vehicle sway when cornering).
Within these systems, the coil-over style suspensions themselves can be threaded, with a multitude of integrated controls that are mechanically pre-configured, such as the height of the vehicle by threading, spring preloads, shock absorber hardness, advance and drop of the wheels. , etc.
And in Formula 1? Are the suspensions very different?
In recent years they have evolved due to the progress of the teams’ own investigations or the new FIA regulations –such as the need for a system that attaches the wheels to the car in the event of an accident so that they do not fly off–. But yes, they are really different.
The principle is similar: shock absorber and spring. Although, in the single-seaters of the great circus, the shock absorbers are gas-powered and control the ‘spring effect’ exerted above all by the torsion bars – a different system to the helical springs of conventional cars. To this are added many other elements of union to the wheels that cover various functions in the single-seater.
Generally, these elements are made of carbon fiber in order to obtain great resistance while maintaining the ideal weight balance. On both axles, those ‘rods’ that are attached to the wheel and hidden inside the car are called wishbones and tie rods , which join the strut over the wheel axles to the vehicle. In general terms, the pull-rod system is usually used, which consists of the compression of the shock absorber and torsion bar being carried out in relation to the level of traction of the wheel, which ‘pulls’ an arm that produces that compression.
In recent years, the old double-shock and double-spring systems have been replaced by a single combination of these two elements that controls the entire assembly, with the pull-rod leading the way in solutions – as opposed to the push-rod , which understands another concept in which it does not pull, but pushes the shock absorber–, since due to its configuration with a tie rod outside the lower triangle, it forces the assembly (of the shock absorber) to move downwards, moving the center of gravity towards the ground of the vehicle as well.
On the other hand, in the front axle, the steering arms are added to control the rotation of the wheels and which must be well aligned with the rest of the components in their connection to the upright, and where the teams usually present different solutions with respect to the position of these ‘triangles’, as is often seen for example in the Monaco circuit.
Aerodynamics influences the suspension of a Formula 1, and vice versa
Not only the forces supported by this assembly while the car travels the asphalt are the only problem that F1 engineers face. Aerodynamics, after all, creates a vertical force that ‘pushes’ the car against the ground. That extra weight must be taken into account and supported by the suspension, and as is evident, it also depends on each circuit.
In Austin, for example, the importance of lateral forces and impacts on the asphalt are greater than the aerodynamic load generated on its straights, which may be more important in the Losail circuit in Qatar, for example.
In this aspect, Mercedes offered an innovation clearly seen in the subjective cameras of Turkey or the COTA , where the rear height of the single-seater descended in a straight line as speed increased, with the aim of reducing aerodynamic resistance.
Christian Horner himself stated that on circuits like the one at the last United States GP, where there are no significant variations in pace, he did not have a great advantage. “But on some circuit, like Jeddah for example, it could be quite a powerful [solution],” the Red Bull boss remarked.
The teams assemble, depending on the circuit and the progress, different suspension systems that include adjustments of the torsion bars, gas pressure of the shock absorbers and the stiffness and shape of the other elements. Something that the pilots also influence with their information and their own driving style.
Innovation, tricks and research that make history
In other times, Lotus and Williams came up with an incredible technical solution regarding car suspensions: the famous electronic or active suspensions .
The idea was developed by Lotus in the 1980s, but it was Williams who in 1992 won the constructors’ and drivers’ championship with Nigel Mansell ; and this new mechanical addition was key that year in Formula 1.
The operation was ‘simple’: a computer as an artificial intelligence that, depending on the forces exerted on the car, controlled and regulated the car’s hydraulic actuators to keep it stable during acceleration, braking or against the lateral forces common in competition .
Finally, and given the enormous difference between Williams’ car and the rest, the FIA prohibited this type of suspension, limiting it to mechanical action only.
The latest innovation in F1 was the Mercedes DAS system in 2020. Dual Axis Steering was a solution whereby the driver could control the convergence of the front axle wheels through a suspension mechanism by pushing or pulling the steering wheel, pull-rod style but in reverse, pulling the wheels. That change in toe-in or toe-out resulted in increased speed down the straights, as the tires offered less resistance to the car’s forward motion.
Although in 2020 the technology was allowed by the FIA, in 2021 a change in regulations made it illegal, so another door was closed to research in suspension systems as it happened in the 90s, although it is a field that is not for to evolve and in which the great teams invest a large amount of resources to win those important tenths in each race.
