The photos that offer clues to Red Bull's rear wing problems

The issues faced by Red Bull began to reveal themselves at the United States Grand Prix, as the team was forced to make repairs to the rear wing’s mainplane during final free practice.

The repairs were largely believed to be caused by the bumpy circuit at COTA, with hairline cracks appearing that the team felt they needed to repair ahead of qualifying.

An interesting note to make is the team had opted for its medium downforce rear wing, whereas in 2019, the last time we raced at COTA, it went for its high downforce configuration.

Meanwhile, the rest of the grid, including closest rival Mercedes trended towards higher downforce packages.

Downforce packages

Red Bull has experimented a lot with switching between its downforce configurations, obviously mindful of Mercedes’ straightline speed advantage.

Even in Mexico, Red Bull clearly went with question marks over which aerodynamic configuration would suit it best, as it trialled the medium downforce rear wing on Perez’s car during first free practice.

Unfortunately the Mexican lost control of his RB16B exiting the final corner and hit the barrier, destroying one of the wings in the team’s available pool.

It’s worth pointing out that teams don’t have an infinite supply of parts on hand, although they do have ‘spare’ parts to cover damage that might occur.

However, with such a tight schedule, including the Mexico, Brazil and Qatar triple-header, the team knew that parts would be at a premium.

The team completed the rest of the weekend in Mexico with its high downforce rear wing, but this didn’t come without its own drama either, as the team was forced to make running repairs ahead of qualifying once more.

This time the team was required to fix the outer section of the top flap and the louvred section of the endplate, as both were showing signs of fatigue.

Problems persisted for Red Bull in Brazil, but it looked like the team had taken note of the issues faced in Mexico, with the louvred section of the wing appearing to feature a similar hotfix and repainted in a black finish, rather than red like the rest of the lower portion of the endplate.

However, it appeared that the fixes made to the mainplane and endplates were beginning to take their toll, as during qualifying it was noted that the rear wing's top flap on Verstappen’s car was oscillating at the end of the pitstraight whilst DRS was deployed.

As a consequence, the team replaced both the rear wing upper flap and the flap snubber for like-for-like components under parc ferme conditions.

Red Bull Racing RB16B rear wing detail

Photo by: Uncredited

It wouldn’t be the last time we’d see them have this issue, as it reared its head once more in Qatar, just a week later.

Having tested both the high and low downforce packages on Friday in Qatar, the team had preferred the medium downforce package for the race.

However, even after several attempts to fix the wing, the DRS actuator, linkages and pivots, the team couldn’t find a way to prevent the unwanted oscillations when the DRS was active.

It’s important to note that the oscillations do not provide a performance advantage but, given the disputes that have arisen in regard to rear wing performance this season, it’s likely that should it occur under race conditions a protest could be in the cards for it being a moveable aerodynamic device.

Furthermore, risking a DNF at this stage in the season would be pivotal in the championship battle and to be avoided at all costs.

Red Bull Racing RB16B DRS actuator and linkage

Photo by: Giorgio Piola

Higher speed challenges

The team has not commented extensively on the cause of the issues it is facing, nor explained whether it’s an issue caused by the team only having two specifications of DRS actuator and linkages at its disposal this season, due to the homologation system that has in-turn created issues with the integrity of the wings.

It could also be related to the number of rear wing assemblies available during this phase of the season that are unable to sustain the loads imparted on them.

In respect of the latter, it’s interesting, as the tracks visited at the back end of the season have higher speed trap figures across the board than the opening four races where Red Bull used its medium downforce rear wing.

For example, qualifying trap figures for Verstappen in Bahrain, Imola, Portimao and Barcelona were 313.6, 291.8, 314.4 and 313kph respectively. Whereas, Istanbul Park, COTA and Interlagos were 322, 318.3 and 318.3kph respectively.

The trap figures vary for the race but tend to trend higher due to the ability to grab the combination of a tow and DRS from a car that’s being lapped.

Red Bull Racing RB16B flexi rear wing

Photo by: Giorgio Piola

The intriguing question this poses, is what role, if any, did the toughening up of the load and deflection tests play in the design resilience of Red Bull’s wings to these higher speed tracks?

After all, a rear wing that was designed to flex rearward over a certain speed will see more load than that one that was originally intended due to the angle of incidence.

The new tests came into force for the French Grand Prix but, with the caveat of a 20% margin for error for the first month of their introduction, which in real terms meant that teams didn’t need to fully comply until the British Grand Prix, with the medium downforce wing used at both events held at the Red Bull Ring.

In the time between the race at Silverstone and their issues at COTA, Red Bull raced the medium downforce rear wing four times and the high downforce package only featured during free practice sessions where the team evaluated its options.

Of these occasions, only one race really stood out in terms of being representative to the top speeds it would encounter in the latter races - Turkey.

The others, including the Hungarian Grand Prix, which is normally considered a high downforce track and makes its choice seem odd, still saw it behind the Mercedes in the speed trap in qualifying.

Only Perez ran the medium downforce package in Russia, as Verstappen was starting from the back with a new power unit, so it was felt he’d make better progress with the low downforce package.

Meanwhile, top speed was also lower for the Dutch GP, owing to the circuit layout. But this didn’t prevent a foreshadowing of its issues to arise as, during Verstappen’s qualifying run, his DRS actuator failed, resulting in him not being able to use DRS out of the last corner. Even so his time was still enough for him to take pole position.

Red Bull Racing RB16B rear wing detail

Photo by: Uncredited

Endplate influence

Returning to the symptoms that have resulted in the running repairs and oscillating top flap, we can see in this image that Red Bull’s endplate is making a bid for freedom in relation to the position of the flap when it’s loaded.

To better understand what’s at play here we must realise that all of the teams approach the design of this area of the endplate differently.

Teams reduce the thickness of the endplate in the region around the mainplane and top flap in order that they might create a set of wing fillet profiles that stay within the bounds of the endplate’s allowable thickness.

Stealing real estate from the endplate to create these additional profiles helps improve the efficiency of the wing and softens the pressure gradient that would otherwise be created between the two surfaces interacting with one another.

As always, each team does so in a unique way, with Red Bull opting to simply have its profiles jut out from the endplate and leave a clearance gap to the slot gap separator housed on the end of the top flap.

Mercedes sacrifices a slither of the fillet profiles width to box them in with another endplate that butts up to the slot gap separator. Meanwhile, Alpine has a solution somewhere in between the two, with a small joint connecting each profile to maintain their proximity to one another (red arrow).

Red Bull Racing RB16B rear wing detail

Photo by: Uncredited

Coupling this lack of rigidity in the overall structure of Red Bull’s wing with the high speed nature of the venues visited over the course of the last few races could answer at least part of the reason as to why it has been struggling with its wings as of late.

But, there is one last aspect of this design that Red Bull use that could be causing some of its issues - the endplate twisting when DRS is deployed.

As we’ve already seen in the image from Brazil, the endplate appears to be flexing, which opens the gap between it and the top flap more than in the rest position, whilst the second most profile appears to be angled away from the flap further still.

If we use this knowledge and look at an image from Hungary with the DRS open we can see that the lower profile is twisted here too, suggesting that when the DRS flap closes it might do so in a way that fouls the profiles and results in the damaged caused to the flap, the pivots and the DRS mechanism. 

Red Bull Racing RB16B rear wing detail

Photo by: Uncredited

The two remaining races are being held at venues that would ordinarily require teams to use their medium downforce packages, which puts Red Bull in quite the quandary.

The question is, will it continue to use the parts it has over the last few grands prix and fix them as they go, or will it arrive with new parts that are similar in design but a little more robust in order to stand up to the forces at hand? Could there even be an all-new design?

The research, design and production of new parts at the end of this season might also be more than it is able to handle, given the cost cap and share of resources needed to develop its car for 2022.