Lewis Hamilton, Mercedes, Alexander Albon, Red Bull, Red Bull Ring, 2020

Red Bull’s protest against Mercedes’ DAS rejected by stewards

2020 F1 season

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Red Bull’s protest against Mercedes over the legality of their dual-axis steering system has been rejected by the stewards at the Austrian Grand Prix.

The protest against the world champions’ new W11 car was lodged by Red Bull following today’s two practice sessions at the Red Bull Ring.

Red Bull objected to the design of the DAS system, which allows Mercedes’ drivers to adjust the toe angle of their front wheels by sliding the steering wheel forwards and backwards.

In their protest, Red Bull queried its compliance with regulations on the cars’ aerodynamic surfaces and suspension. However their claim DAS is part of the car’s steering system, and therefore may not be adjusted while the car is moving, was rejected.

The stewards ruled DAS is “physically and functionally a part of the steering system” and that “it benefits of the implicit exceptions to certain suspension regulations applicable to steering”.

Lewis Hamilton, Mercedes, Red Bull Ring, 2020
Analysis: Why the FIA stewards ruled Mercedes’ DAS is legal
The ruling has no effect on the legality of DAS beyond 2020, however. The FIA has already issued updated regulations for next season, when DAS will be banned.

Stewards’ verdict on Red Bull’s protest against Mercedes

Protest filed by Aston Martin Red Bull Racing against Car number 44*, driven by Lewis Hamilton of the Mercedes-AMG Petronas F1 Team

Stewards Decision: The Protest is rejected as it is not founded.

1. On July 3, 2020, after Free Practice 2 held during the Grand Prix of Austria, counting towards the 2020 FIA Formula One World Championship, Aston Martin Red Bull Racing (“Red Bull”) filed a protest against Car 44 (the “car”), owned by Mercedes-AMG Petronas F1 Team (“Mercedes”).

Red Bull claimed in its protest that the car would be not in compliance with Art 3.8 and 10.2.3 of the 2020 Formula One Technical Regulations. The parties were summoned and heard. The following persons were present during the hearing (in person or via video conference):

On behalf of Red Bull:
– Paul Monaghan
– Adrian Newey
– Jonathan Wheatley

On behalf of Mercedes:
– James Allison
– Ron Meadows
– John Owen
– Andrew Shovlin

On behalf of the FIA Technical Department:
– Nikolas Tombazis

2. The FIA Technical Department carried out an analysis of the Mercedes system and the Stewards inspected the relevant car parts.

3. At the hearing there were no objections against the composition of the Stewards panel or against the procedure of using a video conference call in addition to a face to face hearing. The parties set out oral arguments and addressed the questions asked by the Stewards. The FIA expert was interviewed and explained his written comments.

4. At the hearing the parties referred to the documents submitted. None of the parties submitted further evidence or initiated the hearing of additional persons or conducting further investigations.

The claims of Red Bull:
• The Mercedes DAS design breaches Articles 3.8 and 10.2.3, Aerodynamic Influence and Suspension Geometry respectively, of the 2020 Technical Regulations via the following rationale.

Article 3.8 contains the paragraph:

With the exception of the parts necessary for the adjustment described in Article 3.6.8, any car
system, device or procedure which uses driver movement as a means of altering the aerodynamic
characteristics of the car is prohibited.

Article 10.2.3 states

No adjustment may be made to any suspension system while the car is in motion.

DAS appears to work by changing the toe angle of the front wheels. This is separate in effect to the traditional steering system as it does not involve movement of the steering rack pinion gear.

A conventional steering system can navigate a lap of any circuit and by necessity is granted exemption to Articles 3.8 and 10.2.3. In isolation DAS is incapable of lap navigation and is therefore dependent upon the conventional steering system – i.e. DAS, in changing the toe angle of the wheels is a separate and redundant system.

Alteration of the static toe angle on the front axle will also change the aerodynamic characteristics of an F1 car, typically performed in set-up and prohibited in Parc Ferme. DAS operation, which is a front axle toe angle modifier, will have a measurable aerodynamic effect on the car, whether changing the trajectory or not.

A steering system should alter a car’s trajectory when used. Observation of DAS usage in FP2 indicated deployment in a straight line with no change of trajectory, thus rendering DAS not a steering system.

By observation of the video footage from FP2, use of DAS was not every lap and isolated to in/out or re-charge laps thus it was not a system necessary for use in timed laps, rendering the pimary purpose to be something other than steering.

Subsequent use in a corner cannot recover the breach as the competitor must demonstrate compliance with the regulations at all times during an event, Article 2.7 of the Technical Regulations.

The Technical Regulations do allow multiple steering systems. RBR contend a steering system should have the primary purpose of being able to steer the car. A secondary system that is, on its own, incapable of steering the car is an unnecessary system.

A key discussion point must be why have Mercedes added the DAS system? As mentioned above, judging by practice today, it appears to be used on out and slow laps as a means of adjusting tyre temperature, i.e. its primary purpose is not as a steering system but rather a tyre temperature management system.

In conclusion, DAS is an unnecessary, separate system requiring a separate driver input and using components which are separate in their effect to the main steering system breaching Articles 3.8 and 10.2.3 »

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Mercedes’s arguments in defence:

« DAS is not a suspension system because:

1. It is mounted on the fully sprung side of the car and plays no role in suspending the car, or insulating the car from the undulations on the road surface
2. It is mounted fully on the power assisted steering rack.
3. All it is capable of doing –just like a traditional steering system –is to alter the alignment of the front wheels about the kingpin axis by changing the position of the outboard ends of the steering rack
4. It cannot change the length of any of the suspension members

DAS is a steering system because:

1. Actuating conventional steering moves the wheels in the same direction
2. Actuating DAS moves the wheels in the opposite direction – it is like changing the static toe angle of the steering system
3. Conventional steering often also changes the toe – but it does so as a function of steering angle
4. Changing the toe angle of the wheels changes the forces on the front tyres.
5. Any driver knows that changing the toe makes the car change its steer response (from lazy to nervous) – changing this value while the car is manoeuvring (in corners or on the straights) will cause the car to steer.
6. This is because under all track conditions (except the purely hypothetical situation of zero wind and geometrically perfect track), the difference in load on the tyres from left to right will cause the car to steer when the toe angle is changed.
7. DAS is a steering system that allows the driver to optimise the toe, and therefore the steer response of the car during a run instead of being confined to changing only from run to run.

DAS is a legal steering system because:

1. It fully respects Article 1.2 and 10.4.1 in that it only allows for the alignment of two wheels
2. It is not electronically controlled
3. It passes all the geometrical and safety requirements of 10.4
4. It is a steering system, and so benefits from the same implicit exemptions from article 3.8 as every conventional steering system on the grid
5. We have fully complied with our obligations under Art 2.5 to describe the novel system. »

Conclusions of the Stewards:

Having considered the various statements made by the parties and listened to the expert witness statements made at the hearing, the Stewards determine the following:

The DAS system allows the driver to adjust the toe angle of the front wheels by a longitudinal motion of the steering wheel along the steering column. So the steering wheel has two degrees of freedom:
– Rotational degree of freedom around the steering column axis: this provides the conventional steering response of the car
– Longitudinal degree of freedom along the steering column axis: this steers the wheels independently from each other, thus adjusting the toe.

The DAS is hydraulically-assisted like any conventional Formula 1 steering system, but remains under the full control of the driver at all times. Physically, the DAS is integrated with the conventional steering system of the car.

The Stewards believe DAS is part of the Steering system, albeit not a conventional one. The key challenges to the legality of DAS rely on it not being part of the Steering system. If this were indeed the case, then it would be breaching the following Technical & Sporting Regulations:

1. Article 3.8 (Aerodynamic Influence): the position of the front wheels affects the aerodynamic performance of the car, and is controlled by the driver. An exception is de facto made for steering, otherwise all cars would be illegal. If DAS fell outside this exception, it would be illegal.
2. Article 10.1.2, which states that the front suspension system must be so arranged that its response results only from changes in load applied to the front wheels. Again there is an implicit exception for steering. So if DAS was not part of the steering system, it would fall foul of this regulation too.
3. Article 10.2.1, which states that with the steering wheel fixed, the position of each wheel must be only influenced by (a) its vertical position, and (b) minor compliances. Clearly if the DAS was not considered to be part of the steering, and to hence provide an independent adjustment of the wheel position, it would be illegal. Steering is a de facto exception, and if DAS was not considered to be part of it then it would fall foul of those Articles.
4. Articles 10.2.2 and 10.2.3, related to adjustments of the suspension whilst the car is in motion or powered suspension systems.
5. Article 34.6 of the Sporting Regulations: this forbids an adjustment of suspension in parc fermé. It is, for example, not permitted to adjust the toe angle by mechanically adjusting the length of the steering arms during parc fermé. Clearly (again) steering is a de facto exception, and if DAS was not considered to be part of it then it would fall foul of this Article.

As a general conclusion, it is very simple to conclude DAS would be illegal IF it were not part of the steering system. So the main challenge and debate has to be on whether it can be considered to be part of the steering system.

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The Stewards decide that DAS is a part of the Steering system.

1. Article 1.2 states that “at least two (wheels) are used for steering” and Article 10.4.1 states that “the re-alignment of more than two wheels is not permitted”. These two articles hence limit the number of steered wheels to 2, but crucially no reference is made on that realignment being of a single degree of freedom (i.e. the LH wheel having a single function of position in relation to the RH wheel).
2. There is no direct definition of steering, but one can plausibly suggest that:
a. Steering changes the direction of the car
b. During steering the steered wheels rotate about a vertical or near-vertical axis to change their direction, and hence steer the car.
3. Changes in toe affect the direction of the car in two ways:
a. If toe changes in a corner, the effect will be asymmetric and hence the trajectory of the car will change b. If the driver applies a steering wheel (rotational) input, the response of the car will depend on the toe angle of the wheels, hence the fore-aft position of the DAS will have a direct steering effect.
4. Mechanically, the DAS re-aligns the two front wheels via the same central mechanism that conventional steering does (i.e. the PAS). The fact it acts on the track rod is, we believe, entirely equivalent to the conventional steering.
5. A hydraulically-powered DAS which remains under the full control of the driver is also entirely consistent with the hydraulically-powered conventional steering system.
Because of the above arguments, the Stewards believe that DAS can be legitimately considered to be part of the car’s steering system, and hence that it should be subjected to the same implicit or explicit regulations as the conventional steering system.

The Stewards decide that DAS is not in breach of the suspension-related regulations.

1. Fundamentally suspension has the purpose to insulate the sprung mass of the car from the undulations in the track surface. The alignment of each front wheel (i.e. its steering angle) has an effect on the suspension, but this is incidental. Article 10.2.1 specifically deals with this matter, stating that “With the steering wheel fixed, the position of each wheel centre…etc.”. This Article essentially separates the function of the suspension and that of the steering. It is also clear that the steering wheel position is in this case a two-degree-of-freedom system.
2. Consequentially, the legality of the DAS system is identical to the conventional steering system in terms of the legality under Articles 10.1.2, 10.2.2 and 10.2.3.
3. The legality of the DAS system under other parts of the regulations (Article 3.8 – aerodynamic effect, ride height with steer (TD/003-18), etc.) is equivalent to that of the conventional steering system as the DAS, for the reasons stated, is considered to be part of the car’s steering system.

For the above reasons the Stewards conclude that the DAS system is not part of the suspension, nor can it be considered to illegitimately adjust the suspension.

Therefore the Stewards consider DAS to be a legitimate part of the steering system and hence to satisfy the relevant regulations regarding suspension or aerodynamic influence.

In the opinion of the Stewards, the DAS system is physically and functionally a part of the steering system.

As such, it benefits of the implicit exceptions to certain suspension regulations applicable to steering.

Competitors are reminded that they have the right to appeal certain decisions of the Stewards, in accordance with Article 15 of the FIA International Sporting Code and Article 10.1.1 of the FIA Judicial and Disciplinary Rules, within the applicable time limits.

*A similar document was issued for Valtteri Bottas’s car, number 77

2020 F1 season

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Keith Collantine
Lifelong motor sport fan Keith set up RaceFans in 2005 - when it was originally called F1 Fanatic. Having previously worked as a motoring...

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38 comments on “Red Bull’s protest against Mercedes’ DAS rejected by stewards”

  1. Both the protest and the rejection of the complaint had been more or less anticipated. It’s good Red Bull made the protest, I think, as it clears up the issue for this season before it finally gets going. We still don’t know how much difference the DAS system will make (somewhere between a little and a title-guaranteeing amount).

    1. Josh (@canadianjosh)
      4th July 2020, 0:10

      Increasing speed on the straights and reducing tire wear on the Mercedes will be very advantageous you would think though, any advantage the Mercedes finds and this seems to be a big advantage if the conditions and track hit off together could be a 2014 which wouldn’t hurt my feelings, the engineers drive this sport and to hold them back would be stupid.

    2. I must say that i am quite impressed with finally seeing the WHOLE argument presented here, as well as feeling it was good that they got this done before the first race @david-br!

    3. Ironic that Merc painted their cars black for discrimination.
      I think it is rather indicative of f1’s discrimination when some teams can do “things” and not only get away with no suspicion but also praise and others like Haas for example, get hammered for having a, too close for comfort, hard to police relationship with Ferrari even though it is per regulation, they’re using ferrari’s suspension, powertrain and other bits, whilst racing point, is using a version of last year’s mercedes on the guise that they copied it from pictures. McLaren copied Merc too, yet they failed multiple nose crash tests, and their nose is not as svelte as mercs. Almost as if it is the exact same construction.
      Red Bull rightfully contested DAS.

      Ferrari’s shady pu investigation was deemed inconclusive, it was everyone’s guess that Ferrari was going against the “letter of the law” the rule states ways to circumvent the actual fuel flow are not intended, fia changed the rules guessing they would hurt Ferrari. The rules also state that suspension geometry is not supposed to be altered on track. last year the fia clarified the ruling for 2021 banning such device, they presumably didn’t had the time to ban it for 2020? If so why not let the protest ban the device? A cynic would say the fia and merc entered a deal on this matter.
      I think fans and media are not looking the right way when questioning the sports integrity, we are looking back and missing the front row, for 7 seasons. It doesn’t matter as long the driver I support is winning, and not Vettel or alonso or schumacher.
      At least Das is cool.

      1. and this is a can of worms because as I stated pre-season, anyone can argue that steering the car dynamically changes steering geometry, and this what the fia stated. Good luck now having everyone do active but no active suspension. as laughable as traction control being banned yet pu mapping a track by the millimetre isn’t achieving the same.

      2. “A cynic would say the fia and merc entered a deal on this matter.”

        Whereas a normal person would think an engineer at mercedes has done a very good job at being innovative within a highly constraining set of regulations, and should be celebrated.

        Each to their own I guess.

      3. Ian Stephens
        4th July 2020, 10:40

        When a team of smart engineers come up with an improvement of debatable legality they have two options:
        1. Keep quiet and hope no-one notices, with the risk that someone does and you look very guilty.
        2. Get FIA approval before the season, with the advantage that if you get rejected so does everyone else.

        These are smart guys, so in option 2 they will are very capable of describing the innovation in a way that makes it seem legal (e.g. calling it Dual Access Steering, or implementing it via the steering controls). this has worked for many other devices such as the double diffuser and the knee-operated drag reduction devices.

        Option 1 has also been used, with mixed success. Ferrari were caught out with last year’s fuel flow system.

    4. @canadianjosh Yes, I expect this to be a big race advantage too, presuming they (team and drivers) can work it right.
      @bascb It’s almost as though Red Bull were deliberately being nice and doing everyone a favour by protesting right away. I agree getting the full reasoning is excellent, obviously though that contrasts with the Ferrari decision last year!

  2. Josh (@canadianjosh)
    3rd July 2020, 23:59

    Mercedes I guess after this ruling should be applauded for this innovation. This is why F1 is better than any other Motorsports, the innovation and technology doesn’t sleep, it keeps evolving and gets better and if Red Bull want to fight the Mercs, they better get their DAS installed.

    1. And the sad part is that it’s been banned from next year. Yet another nail in the coffin of innovation.

      1. I disagree.

        Mercedes’ engineers came up with a brilliant device – they keep it for a year. Only for a year, because next year everybody would have it, therefore they would not have an advantage anymore. Since it has zero road relevance, why keep it? It would only increase costs…

        1. Costs hat are subject to a cap so where is the mythical “ increased costs” coming from?
          Road relevance – so what. If everything had to be road relevant we wouldn’t have wings or ground effects.

        2. Mark Collett
          4th July 2020, 6:39

          I believe Red Bull already have there own version.

    2. Biskit Boy (@sean-p-newmanlive-co-uk)
      4th July 2020, 7:07

      I admire Mercedes technical competitiveness, but I’m sorry but it’s laughable to think of DAS as an “innovation”. It’s just a fudge, a definitional and linguistically clever way to describe the obtuse method used to affect the temperature of the front tyres. Specifically, one that is conceived purely to get around the wording of the rule set.

      In reality increasing friction and therefore wear to induce heat, is a technically poor solution. A truly technical innovation to control the temperature of the tyres would maybe have heating and cooling elements built into the tyre. Although illegal in F1 terms, it would be technically impressive and real innovation.

      1. GtisBetter (@)
        4th July 2020, 8:11

        It’s easy to innovate outside of the regulations. It’s hard to design something that is so different and is within the rules. The fact that nobody has done it means that they either thought it was impossible or didn’t think of it at all. It’s something completely new within the rules, so that makes it an innovation.

        1. Biskit Boy (@sean-p-newmanlive-co-uk)
          4th July 2020, 9:35

          Well your definition of innovation is specific to F1 legislature, so in that case yes. My definition is for the world in general, where the rule set is the laws of physics! So not always easy to innovate outside of F1’s regulations, no.

          In my post above I described what real innovation might be. DAS is just an elaborate mechanism designed entirely to outflank a badly written rule. I associate innovation with good science and engineering, not with an ability to outsmart a less than smart arbitrary rule.

          Like I said. I admire Mercedes for what they have done, but its devious more than clever.

          Semi automatic gearboxes, wings, traction control and active suspension, these are innovations. I guess we’ll have to disagree about DAS.

          1. @sean-p-newmanlive-co-uk the use of those aspects in F1 wasn’t that innovative, as most of them had already been developed by others, and often significantly earlier.

            Semi-automatic transmissions were in public use in the 1930s; as for wings, you can find examples back in the late 1920s, and F1’s use in the late 1960s was more a case of copying what sportscars were doing. Mechanical traction control systems were being experimented with in the 1930s, whilst electrical systems became something available for the wider public in the 1970s – maybe, at most, you could claim active suspension, although even then the system that Chapman developed has mostly fallen out of use in favour of simpler systems.

      2. it’s laughable to think of DAS as an “innovation”. It’s just a fudge, a definitional and linguistically clever way to describe the obtuse method used to affect the temperature of the front tyres. Specifically, one that is conceived purely to get around the wording of the rule set

        Mercedes designed DAS with dialogue with the rule makers throughout to ensure that it didn’t contravene the rules. So it’s a system that is designed to fit within the rule set Not get around the rule set.


  3. This ruling centres around distinguishing between what is considered part of the steering assembly and what is the suspension. I find the explanations slightly unsatisfactory but I think ultimately this is a fair decision. Thanks to Keith for posting the whole thing on this forum for us to chat about.

    I wonder if these inchoate definitions of ‘steering’ and ‘suspension’ will spawn more weird and wonderful innovations. They scream loophole to me and better minds than mine will be able to exploit that.

    1. Yes, the stewards seem to have committed to a rather unconventional definition of steering which basically defines it as changing the angle of the wheels around the kingpin, rather than changing the car’s direction of travel. Interesting point you raise about whether this definition will cause the FIA a problem in the future.

  4. Glad that it has been dealt with quickly and that they published the conclusion. It clarifies the matter and prevent the other teams to line up requesting the same clarification. Also good for us to have the actual report for once.

    @coldfly pretty much what you called, well done.
    Next question is, did RBR figured out how it is working? At least they should know if the system they have been thinking of is legal or not…

    1. It could well be that they have the system developed but wanted it to be clear how it can be done to be within the rules. Wouldn’t be surprised if they brought it to the car before too soon @jeanrien

      1. @bascb That was my interrogation yesterday, how much of an actual protest it was rather than receiving reassurance regarding their own system. The way Horner and Binotto speak about it, it doesn’t sound trivial to replicate and fully comply with regulation.

  5. DAllein (@)
    4th July 2020, 0:46

    I don’t believe RBR lodged the protest “just because” or only to have some clarification.
    They really wished to ban the system.

    Glad they failed.

  6. Other than ‘at least two (wheels) are used for steering’ when DAS had the capability to steers the wheels independently from each other, I think the ruling was clear.

    It feels like an surgical operating theatre for Newey to refine his own version of DAS.

  7. Kobe (@im-a-kobe)
    4th July 2020, 2:09

    Wow that is fantastic insight. Great to see that such innovation could be borne from somebody noticing that the regulations didn’t bother to specify that the wheels should rotate in the same direction when somebody steers haha, and it also explains how/why the FIA was able to ban it so quickly. I can see DAS quickly becoming unsafe if implemented indirectly. Kudos to Mercedes for this!

    1. Kobe (@im-a-kobe)
      4th July 2020, 2:10

      Implemented incorrectly*

  8. I wonder how much of this was planned out ahead of time just to formalize what the FIA said back in Feb. Think about it, we didn’t really learn anything new, but there couldn’t be an official ruling until someone made a protest so Red Bull stepped in, made the protest and got it over with quick. Good on the FIA for getting the question out of the way ASAP, just curious about the behind the scenes parts of the sport.

    1. RP (@slotopen)
      4th July 2020, 8:09


      Right, settling the legality of DAS allows the other teams to plan their approach to it.

      I think the shorten season will increase Mercedes advantage as other teams will have fewer races to develop and benefit from their own DAS. Fewer teams are likely to implement it. But it seems Red Bull are the most likely to implement it effectively, hence their interest in ensuring it is legal.

      1. Ian Stephens
        4th July 2020, 10:46

        Also I hear that there is an unofficial agreement between Ferrari and Mercedes not to protest eachother’s cars. That left it to RB to protest this, and Racing Point to question the Ferrari fuel flow bypass.

    2. It certainly reads like this is more or less what Tombazis and/or his FIA technical group formulated as their response to Mercedes in deciding that it was allowed @lancer033 (to subsequently implement a narrower definition of ‘steering’ in next years rules, to stop this going further).

      On the one hand I find it hard to believe Red Bull really believed it would sway the stewards differently, but on the other I do not think they’d have protested just to have it formalised (and Newey did certainly seem quite passionate about claiming aero benefit).

  9. It’s not semantically different from being able to steer the two front wheels independently.
    The rules quoted don’t exclude two steering wheels.
    They just never imagined it would be useful
    A lot of the claimed gain could be had by having the two depend on the degree of steering lock.
    Suspect being able to manage scrub and tyre temps is the reason for second degree of freedom in controls.

    1. Ian Stephens
      4th July 2020, 10:50

      Yes, all the cars move the inside and outside wheels by a different amount when steering. This just changes how that is controlled by the steering wheel.

  10. Now that Mercedes innovation is public. How about the results of Ferrari’s engine inquiry?

    Well done Mercedes, for coming up with a performance boost that not only can’t be proved to be illegal, but is actually within the rules.

  11. This was the price agreed / trade off made between Mercedes and FIA wrt future budget cap etc. Highly selective treatment to keep them in the sport. The audience is the big loser here. Lewis will have the title presented on a plate again, just like intended

    1. Meanwhile back on planet Earth.

    2. “Lewis will have the title presented on a plate again, just like intended.”

      Nobody wants Hamilton to just walk off with the title this year, but the fact remains that someone at Merc came up with something within the regulations, and Red Bull and Ferrari did not.

      Where is the evidence that the Stewards’ ruling relates to the budget cap and keeping them in the sport? That’s a much wider and far reaching deal, definitely not just for one season that will affect the whole structure of an F1 team. What has Tombazis got to do with the budget cap and doing deals with Mercedes, an engineer steeped in Ferrari heritage?

      The only question is whether it is within the technical regulations or not for 2020, unfortunately for you and us, it probably is.

  12. proud_asturian
    4th July 2020, 11:16

    “It’s not cheating when Mercedes do it.”
    – Mercedes FIAMG Petronas

Comments are closed.