FIA explains stronger front wing flexibility tests

 At this weekend’s Spanish Grand Prix, the FIA is introducing a further tightening of the load tests applied to the wings of F1 cars in a bid to address concerns around flexibility and the performance benefits teams might gain through the use of wings that flex under load. 

Photo by Roberto chinchero

Rear wing deformation was initially addressed by the 2025 regulations, in which Article 3.15.17 specified that if 75Kg of vertical load were to be applied on either extremity of the rear wing mainplane, the distance between the mainplane and the flap (also known as ‘slot gap’) should not vary by more than 2mm. 

“The 2025 regulations were designed to counteract the so-called ‘mini-drs effect’ that became quite a talking point in the autumn of last year,” says Tombazis of concerns that rear wings were flexing to the degree that under load a drag reducing gap was appearing between rear wing elements. “That test was applied from the start of the season, but it soon became apparent it was insufficient.” 

In a bid to monitor the success of the regulation, cameras were mounted on cars during free practice sessions at the season-opening Australian Grand Prix and having analysed the footage the FIA concluded that even tougher tests were needed. At the Chinese Grand Prix, the tolerance was reduced to 0.75mm and at the following race, in Japan, to 0.5mm.

“Over a sequence of races at and following the Belgian Grand Prix we installed cameras on the front wings of all cars and again we concluded that the tests would need to be toughened,” says Tombazis. “That conclusion was arrived at quite late in the year, however, and we felt that if we had introduced extra tests at the start of this season, it would have been tough on teams and may have led to existing front wings being scrapped, and extra expense. Therefore, we felt that deferred introduction was more sensible.” 

Photo by Giorgio Piola

The parameters of the tighter tests are defined in revisions to Article 3.15.4 and 3.15.5 of the 2025 Technical Regulations, which respectively govern Front Wing Bodywork Flexibility and Front Wing Flap Flexibility. 

The former originally stated that when 100kg of load is applied symmetrically to both sides of the car the vertical deflection must be no more than 15mm and when the load is applied to only one side of the car the vertical deflection must be no more than 20mm.

However, from this weekend on, when the load is applied symmetrically to both sides of the car the vertical deflection must be no more than 10mm and applied to only one side of the car the vertical deflection must be no more than 15mm.

Regarding Front Wing Flap Flexibility, the regulations stated that “any part of the trailing edge of any front wing flap may deflect no more than 5mm, when measured along the loading axis, when a 6kg point load is applied normal to the flap”. From this weekend the amount of permitted deflection drops to just 3mm. 

original explanation

CREDIT: Explained by FIA.com