Pirelli confirm teams not to blame for Baku tyre failures following investigation

2021 Azerbaijan Grand Prix

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Pirelli has released the findings from its investigation into the tyre failures suffered by two drivers during the Azerbaijan Grand Prix.

Formula 1’s official tyre supplier determined both that its product performed as intended and that teams followed the prescriptions on using them. A new technical directive specifying revised operating parameters is being introduced for the next race.

Max Verstappen and Lance Stroll crashed out of the last round of the world championship after suffering deflations on their left-rear tyres. Both occured at high speed while the drivers were around 30 laps into stints on Pirelli’s C3 compound, which was designated as the hard tyre for the race.

Following the race Pirelli confirmed it had also discovered a cut on a left-rear tyre belonging to Lewis Hamilton which was removed from his car during the red flag stoppage caused by Verstappen’s crash. Hamilton’s cut tyre, also a C3, was analysed by Pirelli at its Milan headquarters along with the two failed tyres and other samples from the event.

In a statement issued today Formula 1’s official tyre supplier said: “There was no production or quality defect on any of the tyres; nor was there any sign of fatigue or delamination. The causes of the two left-rear tyre failures on the Aston Martin and Red Bull cars have been clearly identified. In each case, this was down to a circumferential break on the inner sidewall, which can be related to the running conditions of the tyre, in spite of the prescribed starting parameters (minimum pressure and maximum blanket temperature) having been followed.

“As a result of this analysis, Pirelli have submitted their report to the FIA and the teams. The FIA and Pirelli have agreed a new set of the protocols, including an upgraded technical directive already distributed, for monitoring operating conditions during a race weekend and they will consider any other appropriate actions.”

Red Bull issued a statement affirming it “worked closely with Pirelli and the FIA during their investigation into Max’s tyre failure on lap 47 of the Azerbaijan Grand Prix and can confirm that no car fault was found.

“We adhered to Pirelli’s tyre parameters at all times and will continue to follow their guidance,” said the team.

“We are grateful that following the weekend’s high speed impacts no drivers were injured,” Red Bull added.

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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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60 comments on “Pirelli confirm teams not to blame for Baku tyre failures following investigation”

  1. Forgive me if I’ve missed something…. What was the cause of the failures?!

    1. The root cause is Pirelli make cr*p racing tires and can’t admit it.

      1. They came pretty close to doing just that by openly ruling out misuse by the teams and external factors such as kerbs or debris.

        Even with odd mandated tyre pressures, with the 2021 cars being slowed down to help Pirelli, and with Pirelli dictating how many laps a tyre can be used their tyres still failed, and thereby caused two (very) high speed crashes.

    2. It was not Pirelli’s fault, it was not the teams fault, it was definitely not FIA’s fault, it must have been an act of GOD.

      1. 2.5 acts of GOD, technically :)

    3. @swh1386

      According to Pirelli, they gave the wrong guidance to the teams. Basically, they told the teams that the tyres were capable of working in circumstances that they couldn’t handle.

  2. Finally McLaren have been cleared for possible sabotage. They’re innocent.

  3. So simple terms… Pirelli screwed up but needs a lot of words to hide that.

  4. “down to a circumferential break on the inner sidewall, which can be related to the running conditions of the tyre”
    Am I stupid or did they not explain the cause at all?

    1. Possibly explained in the ‘new protocols … monitoring operational conditions’ as the belief is that some maybe playing with the tyre temps and pressures as their is little or no checks carried out during the race.
      So basically everything team and car wise is above board, but we are going to be checking more during the race.

      1. Tire pressure and tire temp are never constant during a race.
        So monitoring can warn when dangerous levels are reached.
        But still, the tire was not the right choice for this race.

        1. If a tire can do 40 laps it’s the right tire.
          2 years ago they went 1 set harder and the teams only used the c3/4 and the c2 was never used.

          1. But it’s not the same tire. This year there are structural differences

      2. I don’t really see what teams could do as the starting pressures are already higher than teams want & you would think that when they go out on track the pressures are only going to increase as the tires get upto full operating temperature & no team will want to run pressures higher.

        1. Well Autosport, Motorsport.com and plenty of others have been reporting for some time that most teams are bypassing the regs. Thats even if Pirelli actually check the temps and pressures. Which they can’t. Esp at the pit stop phase. Hence why new FIA monitoring regs are coming in from 22.

    2. Then I am also stupid. Can’t find a cause in these words. A bit like, It failed because it broke…

      1. @marcusaurelius Lol funny when you word it that way.

        For me the key words are ‘in spite of the prescribed starting parameters having been followed.’ Pirelli provided an instruction manual to go with their product, but unfortunately it was incomplete and they sent it out with a few pages missing, unbeknownst to the teams.

        “Oopsy. Here now are the pages we meant to put in. Please now follow the Instructions 2.0 to hopefully avoid another oopsy. Please refer to your supercomputers and your lawyers to hopefully sort out our tires. Thank you for ‘choosing’ Pirelli. Putting the rubber to the road. All over the road.”

        1. I find the declarations very political and coordinated.

          If it wasn’t debris, kerbs, the drivers, a “production or quality defect” nor “fatigue or delamination” and teams adhered to “the prescribed starting parameters” then it can only be a design fault.

          The ‘design fault’ was either the tyre (which Pirelli would not admit to), or the user manual (which the legal teams of Pirelli and the teams would indefinitely fight about).
          Hence the weak statement, coordinated with RBR, and the updated (Pirelli will say ‘clarified’, teams will say ‘more (p)restrictive’) user manual.

          Reading between the lines it seems that there was a ‘design’ fault

          1. Coventry Climax
            16th June 2021, 11:31

            That’s exactly my deduction as well. If everything is ‘OK’, according to Pirelli, yet the inner tyrewall just gave up (“a circumferential break on the inner sidewall”), that’s a design fault, and one of the sort that is 1) very grave and very dangerous, and 2) proves that after 10 years, Pirelli still don’t have the expertise to come up with something that’s F1 worthy.

      2. It failed because it broke…

        That’s what I’m reading as well…

  5. I really don’t see how everything worked as intended and two cars still ended up in the wall due to failing tyres.

  6. So they discovered what everybody else already knew, that their product is incapable of working within the parameters set by themselves for such product.

    1. That’s the big problem with Pirelli’s tyres. Even if you accept that their tyres are made to spice up the show through fast degradation – it’s still not acceptable for their tyres to fail so often. Tyres used outside of the intended duration should simply become slow. Not fall apart.

  7. Well at least they didn’t blame it on debris.

    1. someone or something
      15th June 2021, 20:31

      They are. I don’t see the word debris anywhere, but they were able to cross every other conceivable reason off the list, so debris or a sharp-edged kerb it is.

      1. Pray, how does debris on the outside of the tyre cause

        a circumferential break on the inner sidewall


  8. It’s a joke, These tires are a joke and have been for a while now.

    But once again rather than address the actual issue they simply change the regulations in order to cover for the deficiencies of the tires. At no other point in the sports history has it ever worked that way. It’s always been that the tire supplier/s needed to produce, develop & improve it’s produce around the needs of the cars. It’s wrong that the regulations and indeed the cars now have to be modified because the product they are been supplied with is as sub-par as the tires are.

    This is why the rules need to allow for competition. It forces all involved to develop & improve there products & gives teams options to switch if they feel the tires they are using aren’t good enough. Bringing awful tires & forcing everyone to run them even though I think it’s been clear for years that none of the drivers have any trust in them goes against the very spirit of the sport.

    Pirelli have done nothing but continually bring the sport into disrepute & it’s becoming a joke!

    1. Yeah for sure I expect tire pressures to be a lot higher for next few races.
      Which was probably their mistake this race giving too low tire pressures.

    2. You’re missing a step in your analysis. F1 initially set out the tyre requirements that they would only have certain performance characteristics and that they would degrade in performance linearly during use. Both Michelin and Bridgestone took one look at these requirements and made polite noises about not being interested in a 15” tyres format. Even when F1 announced a change to 18” for ‘21 (now ‘22) they made different polite noises about not being interested at this time.
      Only Pirelli put their hand up and said, “Single supplier with improved opportunities for our brand to suffer by our product exploding in 4K slow motion? Side options on being blamed by everyone for boring races and or poor performances? Where do we sign?”
      F1 needs to take the lion’s share of the blame for this. The fact that major tyre manufacturers like Michelin (who are happy to supply other formats) wouldn’t even bid for the contract says everything.

      1. You’re disregarding the fact that the FIA required that the next tire supplier would have to produce 13 inch tires for the first year of the new deal, and THEN switch to 18 inch. For Michelin and Bridgestone, that would’ve meant developing a 13 inch tire from scratch only to use it for a single season. There’s absolutely no business case for either of them to do that. As soon as that clause was added, the chosen supplier was guaranteed to be Pirelli.

      2. Indeed, the teams need to take a significant share of the blame too. There have been many opportunities to resolve the tyre problem but as long as some of the teams believe that they can exploit what is currently available more than their direct competitors they will never vote in the general interests of the sport. This has happened twice recently in 2019 half the teams rejected going back to the 2018 spec and later in the year when the teams rejected the new 2020 design in favour of sticking with the 2019 despite unanimously complaining that those tyres were terrible. The 2020 tyre design was optimised to be faster in the race but slower over a one flying lap and the teams unanimously said no.

        The general uninformed Pirelli bashing is getting tyresome! The cars are heavier than ever, 150kg greater then mid-2000s (when Michelin couldn’t handle the demands at Indy), with the torquiest and most (consistently) powerful engines ever. On 13inch rims that have not been suitable for the demands being placed on them for some time now.

        Long before Baku there were rumblings that the teams were manipulating the FIA tests to operate the tyres outside the prescribed parameters (just like they have been doing with the rear wings). They are only required to run tyres at the minimum pressure when they are fitted to the cars, once on track there is no monitoring to ensure they maintain the mandated pressures. The teams are disingenuous when they claim innocence that they follow the monitoring rules but know full well that they are often operating outside the mandated parameters.

        1. The general uninformed Pirelli bashing is getting tyresome!


      3. @SammyH 13 inch and Bridgestone was never pondering a return. Only Michelin, while Hankook was the only one (besides Pirelli) that actually entered the tender process.

    3. @roger-ayles whilst there might not have been overt regulation changes, there is inevitably the question of whether there were technical directives or other regulatory action going on behind the scenes during those earlier years that were kept out of the public domain.

    4. Even worse is that what they seem to be saying is…

      “the teams weren’t at fault and we weren’t at fault and the track wasn’t at fault but really we’ve added a whole lot more checks now because we secretly believe the teams were at fault by getting around our current set of checks”

      so why bother saying the teams weren’t at fault when they clearly believe that they were.

      1. Because this is marketing.

        1. More fear of the legal guys, and finding words acceptable to both.

      2. @dbradock I see it a bit differently. I think they are admitting fault in as hidden a way as possible. The tires that blew were made properly and not defective, the teams followed the existing parameters, but the additional directives means that Pirelli themselves were not specific enough about how to use their tires.

        I actually find this not unlike the flexy wing issue, which as we have seen seems to have taken a back seat. Why? Because as with the tires, the teams were passing the tests….it’s just that the tests themselves were insufficient. FIA can’t claim illegality on wings that pass their own tests. Pirelli can’t blame teams who were following their own parameters. So all either can do is add more pages to the instruction manuals. Only difference is it is up to the teams to change the wings to comply, but they can’t do anything to change the tires as they don’t make those. Now the teams will have to jump through more TD hoops to help save Pirelli’s skin. Pirelli better hope all the additional checks actually make a difference. I’m not convinced they will. What TD is going to help once the driver is at lap 30? Pit or risk a crash and dnf?

        1. @dbradock I guess Pirelli hopes a slightly different starting pressure or tire blanket temp will help, but how sure can Pirelli be that come lap 30 that starting pressure or temp will have made a difference? The teams will still be monitoring their tires as always, and so then what? If the existing parameters had the tires looking absolutely fine, and then suddenly bang, will now a different starting pressure or temp give the teams tires that will now give warning signs so the team can tell a driver to slow and conserve or pit? And maybe they’re leading a race with someone only a few seconds back?

          Feels to me like Pirelli is in a corner here and now scrambling.

    5. Coventry Climax
      16th June 2021, 11:35


  9. RandomMallard (@)
    15th June 2021, 22:28

    develop & improve there (their) products

    Does nobody remember USA 2005?

    1. RandomMallard (@)
      15th June 2021, 22:29

      Meant as a reply to Roger.

      1. USA 2005 is irrelevant, the problem was caused by increased load due to the high speed and downforce around the banked corner of the Indy circuit. Additionally there was no rule to allow the teams to use whatever tyre was best for the circuit, a major rule failure.

        1. Yes, US GP was added to the calendar spontaneously in the middle of the season. Before the start of the season, Michelin simply couldn’t know they gonna be racing at Indy oval banked corner, also tests were severely limited so it was impossible to calculate the loads… oh, wait a minute…

          In all seriousness, it’s been 16 years, but there are still people defending Michelin over 2005 US GP, and even more – blaming others, FIA or Bridgestone-running teams for not accepting the chicane-idea. Michelin simply failed to provide a product with necessary qualities that time, just like Pirelli keeps failing to do this over the last 10 years.

          1. Yes, US GP was added to the calendar spontaneously in the middle of the season. Before the start of the season, Michelin simply couldn’t know they gonna be racing at Indy oval banked corner, also tests were severely limited so it was impossible to calculate the loads… oh, wait a minute…

            Probably unbeknownst to you, you are pretty close to what really happened, Tim.

            The banked curve had been resurfaced in the months before the race, without informing the tyre suppliers about the increased abrasiveness.
            Firestone had an unrelated test a month before the race, and informed their parent company (Bridgestone) that new tyres had to be developed for F1 as well. They ‘forgot’ to inform the competition, or even the FIA.

            Michelin showed up with slightly improved 2004 tyres, which could not handle the new resurfaced banked corner.
            Bridgestone rocked up with tyres based on the input from Firestone (same company).

  10. tldr: pretty much the tire structure couldnt take the load. Ergo bad design.

    1. So if I buy a tyre for my road car and run it at 3psi instead of 30psi and it explodes, I should blame the tyre manufacturer and make a claim?

      Obviously the teams have been, and will continue to push the boundaries in order to make their cars as fast as they can within the allowed rules, this has nothing to do with Pirelli, Michelin or Bridgestone, none of them should be expected to be able to out think 10 teams of engineers in 10 different cars. If it wasn’t for safety then the best rule would be “here are the tyres”, do what you want, if they blow up it is your fault for pushing them beyond their limits.

      From my memory of the 2005 US grand prix, around the same time tyre rules came into force, because one team had worked out that running their tyres in the opposite direction to the way they had been designed gave them an advantage in certain situations. i.e. run the right rear tyre on the left. Should the blame lie with the tyre companies because they should have foreseen that this might happen? or should the teams take the blame for using the tyre in a way that it was never intended to be used? I suspect the latter.

      I have no doubt that RedBull and Aston Martin had some idea that what they were doing could push the tyre beyond what it was designed to do and possibly exposed the sidewall of the tyre to the inside edge of a ripple strip, grate or debris. I know why Pirelli want to increase the testing because at the end of the day if a driver or spectator is killed it will look like a tyre company fault, not a team fault.

      I suspect a lot of this will be negated with the move to 18″ tyres and smaller sidewalls, but the bit I enjoy about F1 is the teams pushing all these boundaries and thinking outside the circle:).

  11. Fascinating… So we’re led to believe it’s just a coincidence that Hamilton’s cut was also on the left rear. I would have been almost certain that debris or the track was to blame.

    Feels like some politics going on here. With Merc/Red Bull seemingly with the most to lose from the tyre rule changes, I wonder if Domenicali is having much of a say in this.

    1. @skipgamer Yeah it’s a bit of a stretch when the excuse is so vague (related to the running conditions of the tyre). Wouldn’t be the first time Pirelli is ‘helping the show’.

  12. János Henkelmann
    16th June 2021, 1:22

    Pirelli: “No production or quality defect…”

    Call me stupid but if the hard tyre is supposed to last way longer than it did on both cars, it is INDEED a quality defect!

  13. Mark in Florida
    16th June 2021, 1:28

    What a joke this is turning out to be. Pirelli is making the tires worse not better. I’m afraid that we are going to have better handling cars when the new cars come out in 22 but the Pirelli may pops will negate any improvements in the racing. So sad to have a sport hamstrung by terrible tires. I am hoping that I’m wrong but Pirelli will probably deflate my hope suddenly and catastrophically.

  14. I am waiting for Silverstone…

  15. “…in spite of the prescribed starting parameters (minimum pressure and maximum blanket temperature) having been followed.”

    Lawyer-speak for: the prescribed starting parameters are not good enough and we need 12 more pages of restrictions.

  16. The title is misleading since five out of ten teams (including RB and Aston) were running the tyres out of the parameters set by Pirelli.

  17. Do we know if Pirelli tires are this bad for other categories-motorsports too, or only in F1?
    I ask this because i don´t see Pirelli tires exploding or failing catastrophically in other motorsports, so maybe the problem is not with Pirelli per se but the way modern F1 cars chew its tires.
    Maybe, just maybe, when F1 start using bigger rims, with the reduction of lateral wall in the tires, the problem will have a different solution. But right now F1 cars handle so much aerodynamic force that the tires’ lateral walls deform constantly at every corner, lap after lap.
    In Baku it was very clear that Verstappen’s rear left tire exploded at the border between the lateral wall and the racing surface. When the car was on top of a truck, there was a mechanic desperately covering the tire/wheel with a plastic bag, but the camera showed what happened to the tire.
    Pirelli didn´t start making racing tires last week, they have been in the business long enough to learn, and surely they have the resources and R/D power to make tires that don´t explode.
    (Note: I use Michelin rubber in my car.)

    1. Coventry Climax
      16th June 2021, 12:12

      What Pirelli does and creates in/for other types of motorsports, is an irrelevant question, as the tyres needed for F1 are different to the tyres needed for those other types of motorsport. F1 is supposedly the pinnacle of motorsport, so the loads on the F1 tyres can be expected to be higher than anywhere else.
      In other words, we talk about completely different requirements. And they are requirements that are fully known to Pirelli, for years already.
      There’s two options: The FIA asks the impossible, or Pirelli are incapable to create what is needed.
      Two conclusions too: If the task is impossible, Pirelli should tell the world – and the FIA – so, instead of saying they can yet constantly proving they can’t. And if Pirelli claims it’s not their product or their manual (running specifications/parameters) or the teams using them that’s at fault, yet they can not come up with a tyre up to the job, then the FIA should tell Pirelli to go find another job, just like in the real world.
      Sure, Pirelli has a R&D department, but apparently that’s just not good/big/high-tech/advanced/innovative enough to come up with tyres that do not unexpectedly explode, and it hasn’t been for more than 10 years now.

      1. Thanks a lot for the reply, Coventry, even if I don´t agree.
        It is indeed a relevant question, as Pirelli has proven being capable to develop suitable tyres for motorsport, so suggesting that the company is simply unable to develop good F1 tyres doesn´t float, such a big company have enough resources to solve a problem, particularly if their reputation is at stake. Notably, under present ruleset, no other tyre supplier (that I know of) has started to scream for a chance to make tyres for F1… So, just bashing Pirelli is barking at the wrong tree, IMO, or at a tree that is just part of the problem, not the main problem.
        Surely, the tyres are ruining F1. But this is why I feel that the problem is somewhere else. F1 is the pinnacle of motorsport but the cars use such massive tyres, like rubber baloons. During the GP at San Marino is was evident that the rear tyres were deforming at every corner, under the enormous (or “mega”, how the drivers now prefer…) downforce and speed. With a wider rim/smaller lateral wall, the incredibly high lateral forces on the tyre can be much better managed.
        Also, related to the problems in Baku, I would like to know why the issues happened only on rear tyres and not the front ones.

  18. A spade is a spade and in clear plain english the only answer is a design fault.
    Pirelli are there principally to sell more road tyres = $$’s.
    Have already voted with my wallet in dumping absolute cr@p Pirelli P Zero’s & replacing with Michelin P4S4’s – so-o-o much better in mileage/wear/grip.
    After this, doubly glad I did!!!

    Question – saw a photo of Danny Ric’s # 3 after the crash & the left rear tyre was wrecked. Was this a tyre failure as well?

    1. Pirelli’s on my former car were referred to as ‘ditchfinders’. Eagle F1s or Contis all the way…

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