The 5mm rule change that could stymie Oscar Piastri's F1 championship charge
A simple rule change from this weekend's Spanish Grand Prix could put a dampener on Oscar Piastri's charge to a maiden F1 world championship.
A tiny tweak in the technical regulations will come into effect this weekend, with McLaren expected to be the team that suffers the most.
McLaren has been the car to beat this season, winning six of the eight races so far. Part of its advantage has been attributed to the design of the front wing, which flexes significantly under load, boosting top speed.
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The rule change means the so-called 'flexi-wings' must now be stiffened by a third, potentially reducing McLaren's advantage.
A rule change from this weekend's Spanish Grand Prix could put Oscar Piastri's title charge in jeapordy NurPhoto via Getty Images
Engineers up and down pit lane have designed front wings with fingers that flatten as the aerodynamic load increases at high speed. This reduces the downforce created by the front wing, which decreases drag and increases top speed.
In practical terms, this means teams can run a steeper wing angle, which increases grip in the corners, without the usual compromise of a reduced top speed. It's a concept teams have been experimenting with for decades.
The rule change centres around how much the wings bend when weights are placed evenly on either end, and then again when weight is placed only on one side.
From Spain, the wings can flex 10mm (down from 15mm) when 100kg is placed on either side, and 15mm (down from 20mm) when it's placed on only one. The fingers themselves may flex no more than 3mm when a 6kg weight is applied.
The new rules surround the flexibility of the front wing. Getty
In layman's terms, imagine you're driving down the highway at 80km/h and you put your arm out the window with your flattened hand angled downwards. Even if you tense your arm and try to hold it stiff, the wind will push your arm towards the ground.
Now, imagine your arm is pushed down by 15cm. The new rules mean your arm must now be stronger and stiffer, which will mean it can only flex 10cm.
Back on the F1 car, when three of four of these fingers are stacked on top of each other as they are, the effect is compounded.
It means teams will once again be forced into a more significant compromise to find a balance between top-speed and grip.
The changes to the rules were agreed upon in January, but not implemented until Spain – although Red Bull were pushing for an Imola introduction a fortnight ago – to give teams sufficient time to redesign the wings.
McLaren were accused of cheating after the rear wing of Oscar Piastri's car flexed in Azerbaijan last year. FOX Sports
Similar rules for rear wings were introduced for the start of the year, after McLaren mastered what nicknamed the 'mini-DRS', where the main plain of the rear wing flexed more than the smaller top wing, which created a gap, and therefore reduced drag and increased top speed.
The effects of that were most obvious as Piastri battled Charles Leclerc for victory at the Azerbaijan Grand Prix last year, after which McLaren was accused of cheating.
When 75kg is placed on either side of the main wing, the gap between the two may not vary by more than 2mm.
Red Bull has been accusing McLaren of trickery for much of the year, despite the fact the car has constantly passed all existing tests.
Teams will now almost certainly begin a development race to design a wing from material that remains stiff under static load, but flexible under aero load.
The Spanish Grand Prix begins at 11pm Sunday (AEST).
