2021 Azerbaijan Grand Prix - Baku, June 04 - 06

[Jolle]

Yes, teams were massively overheating the tyres for the pressure measurement and then dropped the temps to the working range so they had to mandate max. blanket temps

The tires are checked on the grid, within a pre-determined temperature before the warm-up lap. How and when would they do that?

[nzjrs]

Yes, teams were massively overheating the tyres for the pressure measurement and then dropped the temps to the working range so they had to mandate max. blanket temps

The tires are checked on the grid, within a pre-determined temperature before the warm-up lap. How and when would they do that?

The tire blanket temperature change was made 2018 -> 2019

https://www.salracing.com/story/2019/2/ ... la-1-tires

[RZS10]

That was already a few years ago (nzjrs beat me to pointing that out) and i have no idea, but that was supposedly one of the reasons why they introduced the new maximum temperatures ... theoretically they could have set a pressure, then overheated the tyres for the measurement, and then those would have cooled off between the measurement and the run in quali for example - similar question is: how did some teams (allegedly) manage to run them below the mandated minimum pressures now? There's obviously some way to do it and there were some loopholes and/or opportunities that teams were (allegedly) able to exploit.

[Scappa]

So it seems 5 teams cheat on pressures: the loophole is in the race, only the tires used at the start are checked by the FIA ​​while those mounted in the pitstops are not.
Obviously the advantages in the race are greater durability and better performance lap after lap.

Can we identify the teams by checking the difference in performance between the first and second race stints?
Ferrari is not cheating so can be a term of comparison: in my opinion the teams involved are Rbr, TR, AM, Mercedes and Mclaren.

https://it.motorsport.com/f1/news/f1-gp ... -/6573922/
https://www.formulapassion.it/motorspor ... 70924.html

[Jolle]

That was already a few years ago (nzjrs beat me to pointing that out) and i have no idea, but that was supposedly one of the reasons why they introduced the new maximum temperatures ... theoretically they could have set a pressure, then overheated the tyres for the measurement, and then those would have cooled off between the measurement and the run in quali for example - similar question is: how did some teams (allegedly) manage to run them below the mandated minimum pressures now? There's obviously some way to do it and there were some loopholes and/or opportunities that teams were (allegedly) able to exploit.

It’s even in the rules how long and at what temp you may have each tire in the blankets.

[PlatinumZealot]

Yes, teams were massively overheating the tyres for the pressure measurement and then dropped the temps to the working range so they had to mandate max. blanket temps

The tires are checked on the grid, within a pre-determined temperature before the warm-up lap. How and when would they do that?

Not addressed to me.. But i wasnt even considering blankets.. The brakes.. They rears get so hot they have a shiny foil cover it. The only reason shiny stuff is used is to reflect very high infrared radiation. Meaning the rims get so hot that they dont want that radiation to get back to the brakes when the air flow reduces at lower speeds.

I think some sort of fluidic switch is in the rear upright assembly... The MBGUK probably disabled 100% and those rear brake disks could be two separate pads. One set of pads is for tyre heating. Disable Brake regen and that pad works harder to produce emmense heat, even at low speeds, to prepare the tyre..

Just my speculation of course. But ever since they started using those "tin foil" (haha) rear cake tin covers I have been a bit suspiscious.

[Jolle]

Yes, teams were massively overheating the tyres for the pressure measurement and then dropped the temps to the working range so they had to mandate max. blanket temps

The tires are checked on the grid, within a pre-determined temperature before the warm-up lap. How and when would they do that?

Not addressed to me.. But i wasnt even considering blankets.. The brakes.. They rears get so hot they have a shiny foil cover it. The only reason shiny stuff is used is to reflect very high infrared radiation. Meaning the rims get so hot that they dont want that radiation to get back to the brakes when the air flow reduces at lower speeds.

I think some sort of fluidic switch is in the rear upright assembly... The MBGUK probably disabled 100% and those rear brake disks could be two separate pads. One set of pads is for tyre heating. Disable Brake regen and that pad works harder to produce emmense heat, even at low speeds, to prepare the tyre..

Just my speculation of course. But ever since they started using those "tin foil" (haha) rear cake tin covers I have been a bit suspiscious.

you have to look at the chain of events before the pressure is measured by the FIA. The cars exit the pit, do a couple of install laps, get on the grid and sit there for about 15 minutes with the tires (on which they, I think, didn't do the install laps) sitting in (temperature regulated and controlled) blankets. Then the tires go on the car, are measured...

[Slo Poke]

There are no amount of protocols that will eliminate what was wittinessed during the Baku Grand Prix and I find it appalling that Pirelli have chosen the ethical option to uphold the Pirelli name over and above the welfare of the drivers, which would have been a far more moralistic approach.
So anyway! The reason for the tyre failures is this.
Present day formula one cars are somewhat heavy and that aspect is assisted by downforce, neither of these attributes bode well for the tyres. There is also prodigious amounts of torque put through them. The Pirelli representative, present at Baku, after both incidents is reputed to have stated that he/she didn’t understand why the failures occurred on the rear left tyres when it was the rear right side tyres that were most stressed. That person, whoever it was, does not appear to have much understanding of formula one cars, as both rear tyres are placed under considerable stress when cornering. Add to that the amount of torque applied at or just after the apex and there’s yet another aspect to factor in and that is lateral centrifugal force, brought about by the weight of the car. All of these conditions combine and produce, at least for four or five complete wheel rotations, small but potentially damaging ‘mechanical stress waves’ as the rubber followed by eventually exposed cordage passes through them. They occur deep in the tread, tyre wall interface and form at first instance, micro-fractures. These fractures develope and propagate as the car encounters more and more left turns, eventually exposing the tyre cordage to similar stress. Under such stress the cordage effectively chews at itself until enough heat and weakness has developed, enough so that vertical centrifugal force brought about by the rotational speed of the tread weight destroys the tyre. It’s as simple as that.
As stated at the top of this comment, no amount of protocols will eliminate the situation. It is a design flaw and until rectified the drivers are at risk! For instance does anyone or can anyone recall the famed photograph of Mr. Vettel exiting Eau Rouge on his way to Radillon? The photo’ depicts Mechanical Stress Waves on his rear left tyre and yet during that same race the failures occurred on the right rear tyre’s inside edge. I mention that because the failures are not peculiar to Baku, they can happen anywhere.
To rectify the design Pirelli simply need to alter the inner surface angle of the tyre wall, tread interface, if, as they state, they are open to suggestions!

I do not intend to enter into any debate pertaining to Standing Waves as opposed to Mechanical Stress Waves.

[nzjrs]

I think some sort of fluidic switch is in the rear upright assembly... The MBGUK probably disabled 100% and those rear brake disks could be two separate pads. One set of pads is for tyre heating. Disable Brake regen and that pad works harder to produce emmense heat, even at low speeds, to prepare the tyre..

I agree with PZ that this seems to be what Mercedes are doing - being the only ones clearly seen in Baku - getting their tires to smoke on the grid. 'Brake Magic' mode does adjust the brake balance and energy regeneration and would be consistent with what we saw.

Perhaps Aston Martin just were not able to use that feature from Mercedes as well as their parent team. It therefore makes sense that Pirelli tries to blame its failures on Mercedes and on Aston Martin.



(Pirelli is the real joke here, don't forget)
(p.s. yes, Pirelli has a hard job)

[Wouter]

There are no amount of protocols that will eliminate what was wittinessed during the Baku Grand Prix and I find it appalling that Pirelli have chosen the ethical option to uphold the Pirelli name over and above the welfare of the drivers, which would have been a far more moralistic approach.

As stated at the top of this comment, no amount of protocols will eliminate the situation. It is a design flaw and until rectified the drivers are at risk!

[Slo Poke]

There are no amount of protocols that will eliminate what was wittinessed during the Baku Grand Prix and I find it appalling that Pirelli have chosen the ethical option to uphold the Pirelli name over and above the welfare of the drivers, which would have been a far more moralistic approach.

As stated at the top of this comment, no amount of protocols will eliminate the situation. It is a design flaw and until rectified the drivers are at risk!

Thanks for the thumbs up Wouter!

[PlatinumZealot]

There are no amount of protocols that will eliminate what was wittinessed during the Baku Grand Prix and I find it appalling that Pirelli have chosen the ethical option to uphold the Pirelli name over and above the welfare of the drivers, which would have been a far more moralistic approach.
So anyway! The reason for the tyre failures is this.
Present day formula one cars are somewhat heavy and that aspect is assisted by downforce, neither of these attributes bode well for the tyres. There is also prodigious amounts of torque put through them. The Pirelli representative, present at Baku, after both incidents is reputed to have stated that he/she didn’t understand why the failures occurred on the rear left tyres when it was the rear right side tyres that were most stressed. That person, whoever it was, does not appear to have much understanding of formula one cars, as both rear tyres are placed under considerable stress when cornering. Add to that the amount of torque applied at or just after the apex and there’s yet another aspect to factor in and that is lateral centrifugal force, brought about by the weight of the car. All of these conditions combine and produce, at least for four or five complete wheel rotations, small but potentially damaging ‘mechanical stress waves’ as the rubber followed by eventually exposed cordage passes through them. They occur deep in the tread, tyre wall interface and form at first instance, micro-fractures. These fractures develope and propagate as the car encounters more and more left turns, eventually exposing the tyre cordage to similar stress. Under such stress the cordage effectively chews at itself until enough heat and weakness has developed, enough so that vertical centrifugal force brought about by the rotational speed of the tread weight destroys the tyre. It’s as simple as that.
As stated at the top of this comment, no amount of protocols will eliminate the situation. It is a design flaw and until rectified the drivers are at risk! For instance does anyone or can anyone recall the famed photograph of Mr. Vettel exiting Eau Rouge on his way to Radillon? The photo’ depicts Mechanical Stress Waves on his rear left tyre and yet during that same race the failures occurred on the right rear tyre’s inside edge. I mention that because the failures are not peculiar to Baku, they can happen anywhere.
To rectify the design Pirelli simply need to alter the inner surface angle of the tyre wall, tread interface, if, as they state, they are open to suggestions!

I do not intend to enter into any debate pertaining to Standing Waves as opposed to Mechanical Stress Waves.

Counter point no. 1
The thing with your theory is that the cars today have less downforce and less top speed. Not sure if they are heavier... And the tyres are heavier by a couple kilograms...

So the tyres should be stronger.


Mechanical stress waves as we have seen in F1 slow motion videos reach extreme levels with curb riding, or "tyre shimmy" out of fast corners where the inner tyre lifts a little.
Tyre shimmy... Could be maybe from suspension design or something? ... Or running certain tyre pressures? I have no clue.. An expert would have to say.

I don't blame the tyre structure. I blame the extreme usage of the teams. Pirelli has not designed the tyres for this sort of abuse.

[Wouter]

Not sure if they [the cars] are heavier ... And the tyres are heavier by a couple kilograms...

So the tyres should be stronger.

I don't blame the tyre structure. I blame the extreme usage of the teams.
Pirelli has not designed the tyres for this sort of abuse.

It might be a good idea to do some research before making such statements.

[PlatinumZealot]

Not sure if they [the cars] are heavier ... And the tyres are heavier by a couple kilograms...

So the tyres should be stronger.

I don't blame the tyre structure. I blame the extreme usage of the teams.
Pirelli has not designed the tyres for this sort of abuse.

It might be a good idea to do some research before making such statements.

Race weight.

I don't even know why I respond sometimes. Add something constructive instead of just criticizing all the time. Sheesh.

Have a discussion with me. Make a challenge to any claims! Don't be a negative nancy. Thats not the culture you want right?

Does anyone care about being wrong or right? Learn and we move on. It all resets anyway.

There are group of posters who i like responding to. They know themselves. Big up!

Nothing is too outlandish to discuss and shoot down if needs be.

The clutched MGUH was a mad idea... Mandess... But within thosed discussions.. Though the poster was totally wrong about it... I it forced me to research high speed clutches in proving my argument that the clutch wasn't viable for the design. These sorts of things.

[Stu]

There are no amount of protocols that will eliminate what was wittinessed during the Baku Grand Prix and I find it appalling that Pirelli have chosen the ethical option to uphold the Pirelli name over and above the welfare of the drivers, which would have been a far more moralistic approach.
So anyway! The reason for the tyre failures is this.
Present day formula one cars are somewhat heavy and that aspect is assisted by downforce, neither of these attributes bode well for the tyres. There is also prodigious amounts of torque put through them. The Pirelli representative, present at Baku, after both incidents is reputed to have stated that he/she didn’t understand why the failures occurred on the rear left tyres when it was the rear right side tyres that were most stressed. That person, whoever it was, does not appear to have much understanding of formula one cars, as both rear tyres are placed under considerable stress when cornering. Add to that the amount of torque applied at or just after the apex and there’s yet another aspect to factor in and that is lateral centrifugal force, brought about by the weight of the car. All of these conditions combine and produce, at least for four or five complete wheel rotations, small but potentially damaging ‘mechanical stress waves’ as the rubber followed by eventually exposed cordage passes through them. They occur deep in the tread, tyre wall interface and form at first instance, micro-fractures. These fractures develope and propagate as the car encounters more and more left turns, eventually exposing the tyre cordage to similar stress. Under such stress the cordage effectively chews at itself until enough heat and weakness has developed, enough so that vertical centrifugal force brought about by the rotational speed of the tread weight destroys the tyre. It’s as simple as that.
As stated at the top of this comment, no amount of protocols will eliminate the situation. It is a design flaw and until rectified the drivers are at risk! For instance does anyone or can anyone recall the famed photograph of Mr. Vettel exiting Eau Rouge on his way to Radillon? The photo’ depicts Mechanical Stress Waves on his rear left tyre and yet during that same race the failures occurred on the right rear tyre’s inside edge. I mention that because the failures are not peculiar to Baku, they can happen anywhere.
To rectify the design Pirelli simply need to alter the inner surface angle of the tyre wall, tread interface, if, as they state, they are open to suggestions!

I do not intend to enter into any debate pertaining to Standing Waves as opposed to Mechanical Stress Waves.

Counter point no. 1
The thing with your theory is that the cars today have less downforce and less top speed. Not sure if they are heavier... And the tyres are heavier by a couple kilograms...

So the tyres should be stronger.


Mechanical stress waves as we have seen in F1 slow motion videos reach extreme levels with curb riding, or "tyre shimmy" out of fast corners where the inner tyre lifts a little.
Tyre shimmy... Could be maybe from suspension design or something? ... Or running certain tyre pressures? I have no clue.. An expert would have to say.

I don't blame the tyre structure. I blame the extreme usage of the teams. Pirelli has not designed the tyres for this sort of abuse.

To me it makes absolute sense that the inner shoulder of the less loaded tyre is the failure point; yes both rear tyres are equally loaded by the downforce (roughly…), but suspension geometry will tend to place the outer tyre upright when there is body roll, while the inner shoulder of the other tyre will see higher degradation (this tyre is pulled into a more negative camber and therefore loads the inner shoulder more). Coupled with the high speeds (which is when the tyres failed) and the heavier tyres (more structure in the flat ‘tread’ area could lead to the shoulders seeing higher stress levels). This is all before kerb-running is looked at, as well as operational tyre pressures. It would be interesting to see how tyre pressure data varies with brake temps and tyre temps.

This tyre failure ‘phenomenon’ is nothing new, and is not limited to Pirelli (they were thrown under the bus at Silverstone when tyres were damaged because drivers were cutting the corners and damaging tyres a few years ago (2011?)
Mansell, Adelaide 1986, losing the WDC due to
a tyre failure, there are others

I’m pretty sure that all of the teams have design tricks that they try to use to influence the tyre temperature (whether it is high surface area ‘wavy’ rim profiles or meticulously applied reflective tape - damn, the brake ‘drums’ themselves are only there to control the flow of cool and warm air into the wheels to try and control tyre temperature).

I know this much, Pirelli will never be the good guys in this, no matter who is at fault.