How F1's development battle has swung between Mercedes and Red Bull

Rather than each team having the choice of going for a clean-sheet design, it has been a case of searching for a way to tip the scales in their favour even if they haven't been able to right some of the wrongs of their original 2020 chassis.

The closest of these battles is right at the front of the pack, with Mercedes and Red Bull, plus McLaren and Ferrari duking it out respectively for first and third in the constructors' championship.

Thrown into the mix too were regulation changes, which focused their efforts on reducing the amount of downforce that could be generated. They required the teams to tweak their floor, rear brake duct and diffuser designs, with the long wheelbase lower rake cars seemingly affected more than their shorter, higher rake counterparts.

The Mercedes W12 being from the low-rake school fell back in terms of performance, with the Aston Martin AMR21, which also follows that design philosophy, clearly disadvantaged by the regulation changes too.

Even after a significant development push in the opening phase of the season to help bridge the gap, Aston Martin has been unable to make up the ground it initially lost to its rivals.

In the face of this adversity, and with a car that seemed to suffer from its fair share of instability during pre-season testing, Mercedes remained steadfast in its approach.

It used a pragmatic approach to dial back performance and find a setup that would put it in the hunt alongside Red Bull, whilst largely sticking to its usual plan of introducing upgrade packages at key waypoints during the season.

Red Bull on the other hand, which has often been slow out the blocks in terms of development, opted for a piecemeal approach for 2021, with a constant stream of updates arriving at almost every race and some larger update packages thrown into the mix for good measure.

This came on on top of its decision to spend its two development tokens at the rear of the RB16B to help unlock aerodynamic and mechanical performance that its predecessor did not have on tap.

This redesign of its gearbox carrier gave it license to reorient the suspension too, adopting a similar layout to the one seen on the Mercedes W11. It raised and pushed back the lower elements, in order to clean up the space beneath to improve the pathway for the airflow as it makes its way to the rear of the car.

In contrast to Mercedes, it had been unable to mount the lower rear suspension element as far back, as that would have also required the crash structure to be redesigned, at a cost of two more tokens, which it didn't have at it disposal.

However, Red Bull was able to relocate the upper inboard suspension elements, placing them much higher and rearward than had been the case with the RB16 (small inset).

Red Bull Racing RB16B rear suspension

Photo by: Giorgio Piola

You'll also note the hollow upright extension that the team introduced in 2020 that not only facilitates the high position but also allows air to move rearward without being encumbered, like it would be if it were a solid structure.

Having used its tokens at the rear of the car and having spent much of 2020 responding to a correlation issue between simulation tools at the factory and the performance at track, Red Bull was unable to make any structural changes to its nose assembly going into 2021.

However, resolving some of those aerodynamic inefficiencies was still high on its list of priorities and so a new skirt was added to the section of the cape that lies beneath the chassis for 2021.

Red Bull Racing RB16B front nose comparison

Photo by: Giorgio Piola

This boxes in the area of the car where teams had previously located their turning vanes and provides a channel for the airflow collected beneath the nose in which to flow centrally along the car.

The RB16B's transformation began straight away too, with development parts arriving before the season was even underway.

A new winglet appeared on the underside of the RB16B's aerodynamically faired side impact protection spar during pre-season testing. This seemingly innocuous change undoubtedly helps re-queue the airflow's direction as it passes around the underside of the sidepod and has been an ever-present feature since.

It was far from the only aerodynamic change noted during testing, as Red Bull also looked to optimise the RB16B's floor, taking into account the new regulations.

It had been one of the teams that had tested a 2021 specification floor during 2020, utilising a tapered design much like the regulations had intended. However, this was quickly cast aside as it installed a Z-shaped floor that we'd seen elsewhere and paired it with an outwardly angled strake (Spec 2).

Before the pre-season test was complete it followed this up by adding two more, slightly shorter strakes, just ahead of the rear tyre, in order to work with the angled strake already present just ahead of the rear tyre (Spec 3).

These alterations worked as a way of correcting and enforcing the pre-existing flow conditions on the edge of the floor, and the team's attempts to drive airflow across and around the rear tyre to improve the performance of the diffuser.

In-season push

For the second race of the season, at Imola, Mercedes made some small changes to the W12's floor ahead of the rear tyre and the diffuser.

These optimisations were likely in response to the instability issues that the team had been fighting during pre-season testing, as it took the data collected and used it to find a practical solution to the revised flow structures being created by the new aerodynamic features and tyres for this season.

This resulted in the notch that had been taken out of the vertical strake being restored, whilst the larger more forward mounted central strake ahead of the rear tyre was replaced with a shorter, shark fin-shaped strake mounted closer to the floor's trailing edge.

Reorienting the flow in this region can have a marked effect on the turbulence created by the rear tyre, with the phenomenon known as tyre squirt one of the objectives to resolve.

Red Bull's development assault really got into full swing when the teams arrived in Portugal, with alterations made from front-to-back on the RB16B.

The bargeboard cluster and sidepod deflector array was given attention for the first time in 2021, building on the changes that the team had made in the back end of 2020, whilst also paying attention to their effect on the changes forced upon them by the new regulations downstream.

This resulted in the fins mounted on the bargeboard's footplate being adjusted, whilst both vertical elements in the deflector array were modified.

The forwardmost of these two elements was moved further forward to sit on the leading edge of the floor's axehead, whilst a slot was added to help better influence the airflow. Meanwhile, the lower section of the old forward element was retained, along with the two forward reaching winglets.

At the rear of the deflector assembly, the vertical element, which had previously hung above the floor, was now mounted to it, whilst the slats that made up the Venetian blind-like section were all adjusted to suit their new surroundings.

At the rear of the car the team deployed a new diffuser, with a much slimmer central section that took advantage of the slimline keel created by the new gearbox carrier.

Moving back to the front of the RB16B, it was interesting to see a small tweak to the front brake duct was made that altered the upper portion of the inlet scoop, with three dividing spars, rather than two used, altering the ratio of cool air distributed to each channel.

Red Bull RB16B front brake duct comparison

Photo by: Uncredited

And, it was here that Red Bull made another change for the Spanish Grand Prix, with the spars positions altered once more in the upper section of the scoop.

This kind of change can have a small but tangible effect on cooling the internal components and improving the aerodynamic throughput of the assembly.

Mercedes responds

Monaco provided the backdrop for the first major update that we'd seen from Mercedes during 2021 and it was a planned performance upgrade made specifically for the tight, barrier lined, street circuit.

It was permissible within the scope of the homologation system without the need to spend any tokens either. So, with Mercedes having struggled at this sort of circuit in the past, it made sense for the team to expend some of its resources to try and alleviate its shortcomings.

As can be seen in this comparison of the car from above, the track rod and lower wishbone were redesigned in order that they met the upright further forward than they had before.

The changes made to accommodate a revised track rod and wishbone layout are made clear by the bulkier flexure for the track rod where it connected to the brake duct.

This also meant that, to get a similar volume for the section of the inlet that's meshed off (highlighted in blue) the team had to sacrifice the rest of the inlet and make changes to how it was partitioned.

This also goes to show how the brake duct is used both as a way of cooling the brakes and as a medium for moving airflow through the assembly for aerodynamic gain. The latter was sacrificed to maintain the required level of cooling for the street track.

Red Bull Racing RB16B diffuser comparison

Photo by: Giorgio Piola

Red Bull, meanwhile, had a few new tricks up its sleeve too and even took a leaf out of the Mercedes playbook, as the outer edges of the diffuser were treated to some serrated edges. This is an aerodynamic trick we've seen from Mercedes in various places over the course of the last few years.

Red Bull Racing RB14B front wing detail

Photo by: Uncredited

At the front of the car a new front wing was also at its disposal, with a revised outboard section utilised to help redistribute the ratio between the amount of downforce that can be generated and how much emphasis is placed on creating 'outwash', whereby the airflow is directed around the front tyre.

Red Bull Racing RB16B flexi rear wing

Photo by: Giorgio Piola

A flexi-wing storm that had been brewing behind the scenes was laid to rest in Azerbaijan when the FIA doubled down on new load and deflection tests that were to be introduced at the French Grand Prix by also requiring teams to add reference dots on their wings in order that the governing body might monitor footage collected by the rear facing camera's onboard the cars.

This led to an interesting side narrative to emerge over the course of the next few races, as teams not only fell in line with the new tests but also looked for ways to find the necessary performance they needed for the given circuit.

This has frequently led to teams having different approaches, with their drivers even forced to take a different route depending on how they found the car balance during Friday's free practice sessions.

Red Bull RB16B diffuser detail

Photo by: Giorgio Piola

More optimisation followed at the Styrian Grand Prix for Red Bull, as the serrated edges that had been added to the trailing edge of the Gurney-like diffuser flaps in Monaco were extended across their entire length and added to the curved section of the uppermost flap beside the crash structure.

Then, just a week later, at the Austrian Grand Prix, Red Bull deployed two more updates, as it looked to improve the performance of the front wing and sidepod deflectors.

And, in keeping with a practice that had been established early in the season, Max Verstappen's car received the new parts, whilst Sergio Perez would receive them a race later.

The change made to the front wing revolved around the transition point between the neutral central section and flaps which are critical to generating and tuning the Y250 vortex.

The new design featured a much more abrupt arc in the mainplane in order to alter the strength of the vortex, whilst the flap tips above were also altered in order to take further advantage of the change in vorticity. Meanwhile, the central portion of the deflector array was optimised again too, as the design team added an extra tier to the winglet stack above the floor's axehead and revised the Venetian blind-like slats to match.

Mercedes AMG F1 W12 sidepod deflector floor comparison

Photo by: Giorgio Piola

Mercedes' largest aerodynamic update of the season arrived at the British Grand Prix, when the team unveiled a revised mid section for the W12.

The rollout included the forward vertical deflector being cut down, which in-turn allowed for the Venetian blind-like slats to be extended forward (1). The main vertical deflector was also detached from the sidepod's leading edge wing, removing the arched section that had previously framed the sidepod's shoulder (2).

The 'wave' floor section which had been an imposing feature on the W12 since the start of the season was also tuned (3 & 4) and the single, more prominent floor scroll, was replaced by a pair of scrolls instead (5).

Behind this, two pairs of four angled fins were added, in order to course correct the airflow that moves around the sidepod (6 & 7).

It's at this point that Toto Wolff suggested that Mercedes was done for the season in terms of upgrades.

And whilst it's understandable that it would arrive at Monza with a track specific low downforce rear wing, it was actually a rehash of the wing used in 2020 in any case.

Red Bull Racing RB16B new floor

Photo by: Giorgio Piola

Red Bull continued to pile on the pressure at Silverstone too though, as it added a step ladder-like winglet on the edge of the floor.

It's arrival saw the departure of one of the two shorter strakes added during pre-season testing, as the structure butts up to the point where it was located.

The slotted wing is also angled in the same direction of the strakes, and fans the airflow outward, reinforcing the existing flow structures designed to push airflow across and around the rear tyre.

Red Bull Racing RB16B front brake comparison

Photo by: Giorgio Piola

Another tweak was made to the RB16B's front brake inlet scoop for the Hungarian Grand Prix, as the designers expanded the lower section to create a more squared-off and symmetrical design that not only has an impact on the lower section of the scoop but also the upper corner too (see red line for comparison).

It's unclear if this has a direct correlation with a need for more brake cooling or whether the team felt the need to add some additional aerodynamic support, as whilst the Hungaroring clearly puts an emphasis on the former, the team has continued to use the design at less demanding circuits too.

As both teams once again tried to strike a balance between the downforce and drag levels required to conquer Spa-Francorchamps, another revision was made to the RB16B's floor.

Red Bull not only revised the pre-existing strake mounted on the corner of the Z-shaped floor cutout, but it added another, creating a more defined path for the airflow to follow.

This highlights the stark contrast of where both teams started in terms of their floor designs too, with Mercedes starting its campaign with one of the most complex designs in the field (right) and in some ways having to dilute its original intent in order to find a more consistent performance level under real world conditions.

Meanwhile, Red Bull started out with a more conservative arrangement, similar to what the FIA intended with its new regulations, but added performance as it went along.

Mercedes W12 front wing comparison

Photo by: Giorgio Piola

Despite suggestions from the team that the upgrade package unveiled at Silverstone would be its last major push for the season, Mercedes introduced a new front wing at the Russian Grand Prix.

However, it's not been raced yet. Having been tested during free practice at the last two races it hasn't supplied sufficient improvement to make it onto the car when it counts.

This unraced design sees the ratio of the immovable outer portion of the wing and the outermost section of the upper flaps altered, suggesting the team is looking to trim some of the wing's downforce level, beyond an angle adjustment, whilst also altering the 'outwash' effect the wing creates.

Head to head

As we can see, Mercedes and Red Bull have gone about development in a very different way this season, with both teams having to balance their development resources heading into and during the season.

They are working against the backdrop of the homologation and token system employed by the FIA to reduce costs and limit development, the new regulations, the implications of the resource sliding scale that's been introduced and the arrival of an all-new car in 2022.

It's a difficult balancing act for all of the teams, not just the two leading the way, as juggling all of these factors not only has an impact on 2021 but also had an effect on the 2020 campaign, and will inevitably lead to some making gains in 2022, whilst others make losses.