Everybody immediately after VER's accident and after the race jumping up
and down about the tyres and Pirelli this and Pirelli that.

2 left-rear tyres failures indeed.

But 18 cars didn't seem to have that problem with their left-rears, so
what did VER and Stroll do that the other 18 didn't ?

Certainly a lot of debris on the track at various stages.

Will be interesting to see what the post-mortems on the surviving rears
of the the rest of the field reveal, if anything .

geoff

On 07/06/2021 02:46, geoff wrote:
> Everybody immediately after VER's accident and after the race jumping up
> and down about the tyres and Pirelli this and Pirelli that.
>
> 2 left-rear tyres failures indeed.
>
> But 18 cars didn't seem to have that problem with their left-rears, so
> what did VER and Stroll do that the other 18 didn't ?
>
> Certainly a lot of debris on the track at various stages.
>
> Will be interesting to see what the post-mortems on the surviving rears
> of the the rest of the field reveal, if anything .
>
> geoff

Perreli asked for rear tyre pressures to be increased during the Baku
race, if there is damage to the tyre it would have increased the risk of
a blow-out, as we saw.

Also there is talk about the big temperature changes going from full
sunlight into shade several times in a lap, as much as 20°C difference,
more stress on a tyre with higher pressure.

On Monday, 7 June 2021 at 07:52:15 UTC+1, Dex wrote:
> On 07/06/2021 02:46, geoff wrote:
> > Everybody immediately after VER's accident and after the race jumping up
> > and down about the tyres and Pirelli this and Pirelli that.
> >
> > 2 left-rear tyres failures indeed.
> >
> > But 18 cars didn't seem to have that problem with their left-rears, so
> > what did VER and Stroll do that the other 18 didn't ?
> >
> > Certainly a lot of debris on the track at various stages.
> >
> > Will be interesting to see what the post-mortems on the surviving rears
> > of the the rest of the field reveal, if anything .
> >
> > geoff
> Perreli asked for rear tyre pressures to be increased during the Baku
> race, if there is damage to the tyre it would have increased the risk of
> a blow-out, as we saw.
>
> Also there is talk about the big temperature changes going from full
> sunlight into shade several times in a lap, as much as 20°C difference,
> more stress on a tyre with higher pressure.
High pressure = more risk of debris puncture
Low pressure = more risk of tyre failure under stress / load

They can't win.

LRear not the most stressed tyre at that track and whilst "of course"
Pirelli will say it was a puncture, the absence of prior warning does seem
to suggest that a simple debris related puncture is the most likely scenario.

On 2021-06-06 11:52 p.m., Dex wrote:
> On 07/06/2021 02:46, geoff wrote:
>> Everybody immediately after VER's accident and after the race jumping up
>> and down about the tyres and Pirelli this and Pirelli that.
>>
>> 2 left-rear tyres failures indeed.
>>
>> But 18 cars didn't seem to have that problem with their left-rears, so
>> what did VER and Stroll do that the other 18 didn't ?
>>
>> Certainly a lot of debris on the track at various stages.
>>
>> Will be interesting to see what the post-mortems on the surviving rears
>> of the the rest of the field reveal, if anything .
>>
>> geoff
>
> Perreli asked for rear tyre pressures to be increased during the Baku
> race, if there is damage to the tyre it would have increased the risk of
> a blow-out, as we saw.
>
> Also there is talk about the big temperature changes going from full
> sunlight into shade several times in a lap, as much as 20°C difference,
> more stress on a tyre with higher pressure.

I'm going to ask to see your credentials on tire construction before I
pay much attention to any of that.

19 to 20 psi is an increase of just more than 5%; not a gargantuan
difference.

And going into sunlight doesn't instantly warm the tire by 20°C. Watch
any infrared video of racing tires and you'll see that cornering and
braking change the tire's temperature far more and far more quickly than
that.

<https://www.youtube.com/watch?v=oUohIZEyq0w>

There's no legend for what colours correspond to what temps, but you can
see very clearly what's going on.

The tires come out of the warming blankets hot, but the moment the car
is moving, the air flowing over the tires cools the surface right down.

Then you can see how quickly the surface temperature comes up when the
car brakes and particularly when it corners.

Now imagine how irrelevant sun and shadow are compared to that.

Reported that Pirelli found cut on Hamilton left rear tyre. And left rear took lots of load in last corners after 16.

On 6/7/2021 1:43 PM, crms...@gmail.com wrote:
> Reported that Pirelli found cut on Hamilton left rear tyre. And left rear took lots of load in last corners after 16.
>

Did they find Hamilton's brakes?

On 07/06/2021 17:04, Alan Baker wrote:
> On 2021-06-06 11:52 p.m., Dex wrote:
>> On 07/06/2021 02:46, geoff wrote:
>>> Everybody immediately after VER's accident and after the race jumping up
>>> and down about the tyres and Pirelli this and Pirelli that.
>>>
>>> 2 left-rear tyres failures indeed.
>>>
>>> But 18 cars didn't seem to have that problem with their left-rears, so
>>> what did VER and Stroll do that the other 18 didn't ?
>>>
>>> Certainly a lot of debris on the track at various stages.
>>>
>>> Will be interesting to see what the post-mortems on the surviving rears
>>> of the the rest of the field reveal, if anything .
>>>
>>> geoff
>>
>> Perreli asked for rear tyre pressures to be increased during the Baku
>> race, if there is damage to the tyre it would have increased the risk
>> of a blow-out, as we saw.
>>
>> Also there is talk about the big temperature changes going from full
>> sunlight into shade several times in a lap, as much as 20°C
>> difference, more stress on a tyre with higher pressure.
>
> I'm going to ask to see your credentials on tire construction before I
> pay much attention to any of that.
>

Not mine. Pirelli F1 director, Mario Isola.

“So sometimes you have the main straight that is under the sun and
two-three kilometers in the back that are under the shadow. And the
difference in temperature between the shadow and the sun can be 20
degrees. So it is something to consider.”

https://asnmp.com/2021/06/05/pirelli-has-increased-minimum-rear-tire-pressure-level-for-azerbaijan-gp/

> 19 to 20 psi is an increase of just more than 5%; not a gargantuan
> difference.
>

Didn't say it was.

On 2021-06-07 2:50 p.m., Dex wrote:
> On 07/06/2021 17:04, Alan Baker wrote:
>> On 2021-06-06 11:52 p.m., Dex wrote:
>>> On 07/06/2021 02:46, geoff wrote:
>>>> Everybody immediately after VER's accident and after the race
>>>> jumping up
>>>> and down about the tyres and Pirelli this and Pirelli that.
>>>>
>>>> 2 left-rear tyres failures indeed.
>>>>
>>>> But 18 cars didn't seem to have that problem with their left-rears, so
>>>> what did VER and Stroll do that the other 18 didn't ?
>>>>
>>>> Certainly a lot of debris on the track at various stages.
>>>>
>>>> Will be interesting to see what the post-mortems on the surviving rears
>>>> of the the rest of the field reveal, if anything .
>>>>
>>>> geoff
>>>
>>> Perreli asked for rear tyre pressures to be increased during the Baku
>>> race, if there is damage to the tyre it would have increased the risk
>>> of a blow-out, as we saw.
>>>
>>> Also there is talk about the big temperature changes going from full
>>> sunlight into shade several times in a lap, as much as 20°C
>>> difference, more stress on a tyre with higher pressure.
>>
>> I'm going to ask to see your credentials on tire construction before I
>> pay much attention to any of that.
>>
>
> Not mine. Pirelli F1 director, Mario Isola.
>
> “So sometimes you have the main straight that is under the sun and
> two-three kilometers in the back that are under the shadow. And the
> difference in temperature between the shadow and the sun can be 20
> degrees. So it is something to consider.”
>
>
> https://asnmp.com/2021/06/05/pirelli-has-increased-minimum-rear-tire-pressure-level-for-azerbaijan-gp/

And that was in relation to managing tire wear...

....because the TRACK is 20 degrees cooler or hotter.

And we already know from what Pirelli has said that whatever caused the
failures, it wasn't excess tread wear.

>
>
>
>> 19 to 20 psi is an increase of just more than 5%; not a gargantuan
>> difference.
>>
>
> Didn't say it was.

You strongly implied it was a significant factor.

On 8/06/2021 1:40 am, Matt Larkin wrote:
> On Monday, 7 June 2021 at 07:52:15 UTC+1, Dex wrote:
>> On 07/06/2021 02:46, geoff wrote:
>>> Everybody immediately after VER's accident and after the race jumping up
>>> and down about the tyres and Pirelli this and Pirelli that.
>>>
>>> 2 left-rear tyres failures indeed.
>>>
>>> But 18 cars didn't seem to have that problem with their left-rears, so
>>> what did VER and Stroll do that the other 18 didn't ?
>>>
>>> Certainly a lot of debris on the track at various stages.
>>>
>>> Will be interesting to see what the post-mortems on the surviving rears
>>> of the the rest of the field reveal, if anything .
>>>
>>> geoff
>> Perreli asked for rear tyre pressures to be increased during the Baku
>> race, if there is damage to the tyre it would have increased the risk of
>> a blow-out, as we saw.
>>
>> Also there is talk about the big temperature changes going from full
>> sunlight into shade several times in a lap, as much as 20°C difference,
>> more stress on a tyre with higher pressure.
> High pressure = more risk of debris puncture
> Low pressure = more risk of tyre failure under stress / load
>
> They can't win.
>
> LRear not the most stressed tyre at that track and whilst "of course"
> Pirelli will say it was a puncture, the absence of prior warning does seem
> to suggest that a simple debris related puncture is the most likely scenario.

I disagree. Same compound, same age and about the same place in it's 'cycle'? Not to mention how
much time Pirelli spent trying to cover Verstappens tyre with a tarp when it was on the truck and
shield it from cameras.

From what I could see of the tyre in Sky close-ups there didn't appear to be a single point of
failure, the whole of the inside sidewall seemed to have come away from the tread. It almost looked
as if it had frayed and thinned at the point of failure. However I could only see a little more
than half of the circumference of the tyre.

I don't know if we'll ever know the truth. Italian companies in F1 seem to be able to obscure it.
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy little classification
in the DSM"
David Melville

This is not an email and hasn't been checked for viruses by any half-arsed self-promoting software.

On 2021-06-07 5:35 p.m., ~misfit~ wrote:
> On 8/06/2021 1:40 am, Matt Larkin wrote:
>> On Monday, 7 June 2021 at 07:52:15 UTC+1, Dex wrote:
>>> On 07/06/2021 02:46, geoff wrote:
>>>> Everybody immediately after VER's accident and after the race
>>>> jumping up
>>>> and down about the tyres and Pirelli this and Pirelli that.
>>>>
>>>> 2 left-rear tyres failures indeed.
>>>>
>>>> But 18 cars didn't seem to have that problem with their left-rears, so
>>>> what did VER and Stroll do that the other 18 didn't ?
>>>>
>>>> Certainly a lot of debris on the track at various stages.
>>>>
>>>> Will be interesting to see what the post-mortems on the surviving rears
>>>> of the the rest of the field reveal, if anything .
>>>>
>>>> geoff
>>> Perreli asked for rear tyre pressures to be increased during the Baku
>>> race, if there is damage to the tyre it would have increased the risk of
>>> a blow-out, as we saw.
>>>
>>> Also there is talk about the big temperature changes going from full
>>> sunlight into shade several times in a lap, as much as 20°C difference,
>>> more stress on a tyre with higher pressure.
>> High pressure = more risk of debris puncture
>> Low pressure = more risk of tyre failure under stress / load
>>
>> They can't win.
>>
>> LRear not the most stressed tyre at that track and whilst "of course"
>> Pirelli will say it was a puncture, the absence of prior warning does
>> seem
>> to suggest that a simple debris related puncture is the most likely
>> scenario.
>
> I disagree. Same compound, same age and about the same place in it's
> 'cycle'? Not to mention how much time Pirelli spent trying to cover
> Verstappens tyre with a tarp when it was on the truck and shield it from
> cameras.
>
> From what I could see of the tyre in Sky close-ups there didn't appear
> to be a single point of failure, the whole of the inside sidewall seemed
> to have come away from the tread. It almost looked as if it had frayed
> and thinned at the point of failure. However I could only see a little
> more than half of the circumference of the tyre.

Riiiiiiight.

Because a tire that deflates at 200 mph isn't going to get damage just
be being deflated...

>
> I don't know if we'll ever know the truth. Italian companies in F1 seem
> to be able to obscure it.

And nothing like a little bigotry to end it!

On 8/06/2021 12:35 pm, ~misfit~ wrote:
> On 8/06/2021 1:40 am, Matt Larkin wrote:
>> On Monday, 7 June 2021 at 07:52:15 UTC+1, Dex wrote:
>>> On 07/06/2021 02:46, geoff wrote:
>>>> Everybody immediately after VER's accident and after the race jumping up
>>>> and down about the tyres and Pirelli this and Pirelli that.
>>>>
>>>> 2 left-rear tyres failures indeed.
>>>>
>>>> But 18 cars didn't seem to have that problem with their left-rears, so
>>>> what did VER and Stroll do that the other 18 didn't ?
>>>>
>>>> Certainly a lot of debris on the track at various stages.
>>>>
>>>> Will be interesting to see what the post-mortems on the surviving rears
>>>> of the the rest of the field reveal, if anything .
>>>>
>>>> geoff
>>> Perreli asked for rear tyre pressures to be increased during the Baku
>>> race, if there is damage to the tyre it would have increased the risk of
>>> a blow-out, as we saw.
>>>
>>> Also there is talk about the big temperature changes going from full
>>> sunlight into shade several times in a lap, as much as 20°C difference,
>>> more stress on a tyre with higher pressure.
>> High pressure = more risk of debris puncture
>> Low pressure = more risk of tyre failure under stress / load
>>
>> They can't win.
>>
>> LRear not the most stressed tyre at that track and whilst "of course"
>> Pirelli will say it was a puncture, the absence of prior warning does seem
>> to suggest that a simple debris related puncture is the most likely scenario.
>
> I disagree. Same compound, same age and about the same place in it's 'cycle'? Not to mention how
> much time Pirelli spent trying to cover Verstappens tyre with a tarp when it was on the truck and
> shield it from cameras.
>
> From what I could see of the tyre in Sky close-ups there didn't appear to be a single point of
> failure, the whole of the inside sidewall seemed to have come away from the tread. It almost looked
> as if it had frayed and thinned at the point of failure. However I could only see a little more
> than half of the circumference of the tyre.
>
> I don't know if we'll ever know the truth. Italian companies in F1 seem to be able to obscure it.

I was just offered this by the youtube algorithm:
<https://youtu.be/1a4E4Vy8e58>
"Why Formula 1 Tyres Failed in the Azerbaijan Grand Prix" by Driver61
He seems to be a clever chap as he agreed with me. ;)
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy little classification
in the DSM"
David Melville

This is not an email and hasn't been checked for viruses by any half-arsed self-promoting software.

On 2021-06-07 7:39 p.m., ~misfit~ wrote:
> On 8/06/2021 12:35 pm, ~misfit~ wrote:
>> On 8/06/2021 1:40 am, Matt Larkin wrote:
>>> On Monday, 7 June 2021 at 07:52:15 UTC+1, Dex wrote:
>>>> On 07/06/2021 02:46, geoff wrote:
>>>>> Everybody immediately after VER's accident and after the race
>>>>> jumping up
>>>>> and down about the tyres and Pirelli this and Pirelli that.
>>>>>
>>>>> 2 left-rear tyres failures indeed.
>>>>>
>>>>> But 18 cars didn't seem to have that problem with their left-rears, so
>>>>> what did VER and Stroll do that the other 18 didn't ?
>>>>>
>>>>> Certainly a lot of debris on the track at various stages.
>>>>>
>>>>> Will be interesting to see what the post-mortems on the surviving
>>>>> rears
>>>>> of the the rest of the field reveal, if anything .
>>>>>
>>>>> geoff
>>>> Perreli asked for rear tyre pressures to be increased during the Baku
>>>> race, if there is damage to the tyre it would have increased the
>>>> risk of
>>>> a blow-out, as we saw.
>>>>
>>>> Also there is talk about the big temperature changes going from full
>>>> sunlight into shade several times in a lap, as much as 20°C difference,
>>>> more stress on a tyre with higher pressure.
>>> High pressure = more risk of debris puncture
>>> Low pressure = more risk of tyre failure under stress / load
>>>
>>> They can't win.
>>>
>>> LRear not the most stressed tyre at that track and whilst "of course"
>>> Pirelli will say it was a puncture, the absence of prior warning does
>>> seem
>>> to suggest that a simple debris related puncture is the most likely
>>> scenario.
>>
>> I disagree. Same compound, same age and about the same place in it's
>> 'cycle'? Not to mention how much time Pirelli spent trying to cover
>> Verstappens tyre with a tarp when it was on the truck and shield it
>> from cameras.
>>
>>  From what I could see of the tyre in Sky close-ups there didn't
>> appear to be a single point of failure, the whole of the inside
>> sidewall seemed to have come away from the tread. It almost looked as
>> if it had frayed and thinned at the point of failure. However I could
>> only see a little more than half of the circumference of the tyre.
>>
>> I don't know if we'll ever know the truth. Italian companies in F1
>> seem to be able to obscure it.
>
> I was just offered this by the youtube algorithm:
> <https://youtu.be/1a4E4Vy8e58>
> "Why Formula 1 Tyres Failed in the Azerbaijan Grand Prix" by Driver61
> He seems to be a clever chap as he agreed with me. ;)

One little problem with his "expert's" analysis:

The left rear was not the most highly loaded tire, so if this was a
failure due to repeated load, why would it have failed first?