Push-rod and pull-rod suspension are phrases which can be used liberally in Formula 1 to explain the configuration of groups’ rear and entrance suspension layouts. But what’s pull-rod and push-rod suspension? What’s the distinction between the 2? And is one higher than the opposite?
Suspension, and why it is necessary
Formula 1 drivers – any drivers – need as a lot of the tyres involved with the floor of the highway as a lot as doable. More tyre contact means extra grip, which implies they will get extra energy down, and subsequently go quicker.
When there is a bump within the highway, equivalent to a kerb on an F1 circuit, the tyre runs over it and a power is utilized to the tyre and the wheel.
Without suspension, the chassis of the automotive would basically be hooked up to the wheels, so any power could be utilized to the wheels and the chassis. This wouldn’t solely make for a severely uncomfortable trip, however it might imply that the automotive’s chassis would bounce uncontrollably over any kerbs, additionally inflicting the wheels to bounce and lose grip with the highway.
Suspension nonetheless permits the power of the bump and the kinetic power to be saved by a spring, which is then compressed, absorbing the power transferred by that bump within the highway and permitting all 4 tyres to grip the highway. That is, except a driver takes “too much kerb”, like within the picture under…
How does F1 suspension differ to highway automotive suspension?
All 4 wheels of the F1 automotive are independently sprung as they use a ‘double wishbone’ design. All 4 wheels subsequently transfer independently relying on the forces utilized to every nook of the automotive. Some efficiency highway vehicles and different racing vehicles additionally use this suspension set-up.
However, the supplies – together with carbon fibre – utilized in F1 vehicles are lighter and stronger, and costlier than these utilized in most highway vehicles.
F1 vehicles not solely should cope with immense forces utilized by kerbs, particles, and no matter else they could encounter on the monitor, however they’re additionally continually being pushed down by downforce – not like the overwhelming majority of highway vehicles. F1 suspension must be sturdy sufficient to face up to that.
The components connecting the tyre to the suspension are sometimes seen in open-wheel vehicles and F1 isn’t any completely different. Being uncovered, these seen components additionally play an necessary aerodynamic position in an F1 automotive.
On a present F1 automotive, there are a number of factors connecting the entrance wheels to the chassis. On the highest and backside, there are wishbones. The higher wishbone is generally shorter than the decrease wishbone on the entrance of the automotive, resulting in ‘unfavourable camber’ – the tyres slope diagonally after they’re stationary. In an F1 setting, unfavourable camber ensures higher contact between the tyre and the highway and extra even tyre put on.
Between the wishbones, each on the entrance and rear of the automotive there is a suspension rod, which runs from the highest of the wheel uprights to the suspension spring. In an F1 automotive, this spring is a horizontally-mounted spring that ‘twists’ when power is utilized to it. This is generally known as a ‘torsion spring’.
On a highway automotive, these springs usually run vertically. Sometimes you may see the spring should you peer via the wheel-arch of a highway automotive, notably if it is sporting a double wishbone design.
Finally, as in a highway automotive, F1 vehicles have ‘dampers’ which cease the spring from bouncing up and down uncontrollably. Dampers include gasoline (or oil or fluid, in older highway vehicles) that dissipates among the power utilized to the spring. In an F1 automotive, virtually every part is geared in direction of efficiency slightly than consolation and so groups will tune suspension and damper stiffness relying on the circuit. At Monaco, groups would possibly go one step additional and match new steering arms to their vehicles to make sure a larger steering angle.
Pull-rod vs push-rod – what is the distinction?
That rod which connects the highest of the wheel to the torsion spring is named the ‘pull-rod’ or ‘push-rod’. That’s as a result of the rod will be mounted to ‘pull’ or ‘push’ that spring.
In a pull-rod configuration, the rod is mounted at a diagonal angle from a low level on the chassis, as much as the next level on the wheel meeting. When a tyre goes over a bump, the wheel pulls the torsion spring by way of the pull-rod, pulling the rod up and outwards from the chassis.
In a push-rod configuration, it is mounted the other approach, so once more at a diagonal angle, however increased on the chassis and decrease on the wheel meeting. When the tyre goes over a bump, the wheel pushes the torsion spring by way of the push-rod, pushing the rod upwards and in direction of the chassis.
Play the brief clip under for a visible demonstration of the 2 completely different techniques.
TECH TALK: What’s the distinction between pull-rod and push-rod suspension?
Which is healthier?
It’s not straightforward to make a blanket judgement on whether or not push-rod or pull-rod is healthier. Different groups run completely different configurations on the entrance and rear of their vehicles.
Push-rod suspension would possibly make the springs and dampers simpler to entry as they’re mounted increased up within the automotive, however different elements may be more durable to entry in consequence. Push-rod can also be mounted increased on the automotive, rising the automotive’s centre of gravity. Teams will think about complexity and price, too – however aerodynamic and efficiency positive aspects can be prioritised.
As with each element on an F1 automotive, altering the suspension configuration can have a knock-on have an effect on and alter the behaviour of the remainder of the automotive in myriad methods.
For extra on the professionals and cons of every system, tap here to watch experts Albert Fabrega and Sam Collins explain all in F1 TV’s Tech Talk show.
Teams and their suspension configurations*
|Red Bull||Front: Pull-rod; Rear: Push-rod|
|Aston Martin||Front: Push-rod; Rear: Pull-rod|
|Mercedes||Front: Push-rod; Rear: Pull-rod|
|Ferrari||Front: Push-rod; Rear: Pull-rod|
|McLaren||Front: Pull-rod; Rear: Pull-rod|
|Alpine||Front: Push-rod; Rear: Push-rod|
|Haas||Front: Push-rod; Rear: Pull-rod|
|Alfa Romeo||Front: Push-rod; Rear: Push-rod|
|AlphaTauri||Front: Push-rod; Rear: Push-rod|
|Williams||Front: Push-rod; Rear: Pull-rod|
|*As of the 2023 Australian GP|