Mercedes W11

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F1Krof
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Re: Mercedes W11

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I don't think though it's the matter of just ripping some downforce and you won't overheat the tires. Most of the time, it's the sliding (cause by lower downforce levels) that cause those lateral forces to destroy the tires rather than longitudinal forces generated by higher downforce. In fact, come to think about it, more downforce would have helped to mitigate the problem.
Wroom wroom

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atanatizante
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Re: Mercedes W11

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F1Krof wrote:
Wed Aug 12, 2020 2:26 pm
I don't think though it's the matter of just ripping some downforce and you won't overheat the tires. Most of the time, it's the sliding (cause by lower downforce levels) that cause those lateral forces to destroy the tires rather than longitudinal forces generated by higher downforce. In fact, come to think about it, more downforce would have helped to mitigate the problem.
With tyres in F1, it`s not so simple ...
If you want you could get some detailed info here right from Mercs tyre manager or whatever they call it:

There are at least 4 main factors for tyre behaviour: track temp, pressure, tyre compound/operation window and DF levels

As I understand, sliding happens when you said that DF levels are low but it`s not enough: there are the other 3 factors that come into account ... for instance if you have to low tyre pressure and tones of DF this could lead the tyre to slide more ... just indulge me and see that above video ... it worth it, believe me :) ...
"I don`t have all the answers. Try Google!"
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atanatizante
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Re: Mercedes W11

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GPR-A wrote:
Wed Aug 12, 2020 2:10 pm

They can rip a bit of downforce off, as their competitors are miles behind and avoid putting so much load in tyres and still be ahead! Induce a bit of understeer and go slightly slower through the corners, but it would allow them a bit more straight line speed, which they would anyway do in Spa and Monza. That is much more easier to do, while they build better solution to better manage the tyres with their full downforce package, if the speculation of that article is indeed true. I have stopped believing some of these hollywood paparazzi guys, masquerading as F1 journalists, long ago.

In the recent debrief, Shovlin just says they were slower as they needed to manage the tyres, but doesn't actually go in detail about what exact car problem made them slower.
Hi GPR-A!

Generally, I like your posts and this time you are right: my above statements are all speculations ...

But I have to remind you that it`s not so simple to trim some DF levels at the back coz you need to compensate at the front axle in order to get a balanced car ... unfortunately, this action will also trim diffuser DF levels which will decrease further their rear DF levels ...

So having to change their optimum aero platform this could lead to a negative domino effect, don`t you think? :D ...
"I don`t have all the answers. Try Google!"
Jesus

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Big Tea
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Re: Mercedes W11

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atanatizante wrote:
Wed Aug 12, 2020 3:22 pm
GPR-A wrote:
Wed Aug 12, 2020 2:10 pm

They can rip a bit of downforce off, as their competitors are miles behind and avoid putting so much load in tyres and still be ahead! Induce a bit of understeer and go slightly slower through the corners, but it would allow them a bit more straight line speed, which they would anyway do in Spa and Monza. That is much more easier to do, while they build better solution to better manage the tyres with their full downforce package, if the speculation of that article is indeed true. I have stopped believing some of these hollywood paparazzi guys, masquerading as F1 journalists, long ago.

In the recent debrief, Shovlin just says they were slower as they needed to manage the tyres, but doesn't actually go in detail about what exact car problem made them slower.
Hi GPR-A!

Generally, I like your posts and this time you are right: my above statements are all speculations ...

But I have to remind you that it`s not so simple to trim some DF levels at the back coz you need to compensate at the front axle in order to get a balanced car ... unfortunately, this action will also trim diffuser DF levels which will decrease further their rear DF levels ...

So having to change their optimum aero platform this could lead to a negative domino effect, don`t you think? :D ...
Would removing down force not just increase slip angles and not only ware the rubber but (friction) add more heat?
Rear tyres more so, which are where the damage was last week?
When arguing with a fool, be sure the other person is not doing the same thing.

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dans79
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Re: Mercedes W11

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Big Tea wrote:
Wed Aug 12, 2020 3:38 pm
atanatizante wrote:
Wed Aug 12, 2020 3:22 pm
GPR-A wrote:
Wed Aug 12, 2020 2:10 pm

They can rip a bit of downforce off, as their competitors are miles behind and avoid putting so much load in tyres and still be ahead! Induce a bit of understeer and go slightly slower through the corners, but it would allow them a bit more straight line speed, which they would anyway do in Spa and Monza. That is much more easier to do, while they build better solution to better manage the tyres with their full downforce package, if the speculation of that article is indeed true. I have stopped believing some of these hollywood paparazzi guys, masquerading as F1 journalists, long ago.

In the recent debrief, Shovlin just says they were slower as they needed to manage the tyres, but doesn't actually go in detail about what exact car problem made them slower.
Hi GPR-A!

Generally, I like your posts and this time you are right: my above statements are all speculations ...

But I have to remind you that it`s not so simple to trim some DF levels at the back coz you need to compensate at the front axle in order to get a balanced car ... unfortunately, this action will also trim diffuser DF levels which will decrease further their rear DF levels ...

So having to change their optimum aero platform this could lead to a negative domino effect, don`t you think? :D ...
Would removing down force not just increase slip angles and not only ware the rubber but (friction) add more heat?
Rear tyres more so, which are where the damage was last week?
It's not exactly that simple, because everything in f1 has 2 dozen inputs, and their all interrelated.

For example you could counteract the the increased slip angle by decreasing camper and increasing the size of the contact patch. Then you tell the drivers easier though the turns because they will be faster on the straits.
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Hoffman900
Hoffman900
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Re: Mercedes W11

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High downforce reduces slip but will put more load on the tire and increase deformation, which will also increase heat. Also, higher loads will increase heat... this is why semi-trucks that exceed weight limits often suffer from blowouts.

You guys have seen how much the tire deforms under load, correct?
Last edited by Hoffman900 on Wed Aug 12, 2020 3:51 pm, edited 1 time in total.

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Big Tea
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Re: Mercedes W11

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dans79 wrote:
Wed Aug 12, 2020 3:47 pm
Big Tea wrote:
Wed Aug 12, 2020 3:38 pm
atanatizante wrote:
Wed Aug 12, 2020 3:22 pm


Hi GPR-A!

Generally, I like your posts and this time you are right: my above statements are all speculations ...

But I have to remind you that it`s not so simple to trim some DF levels at the back coz you need to compensate at the front axle in order to get a balanced car ... unfortunately, this action will also trim diffuser DF levels which will decrease further their rear DF levels ...

So having to change their optimum aero platform this could lead to a negative domino effect, don`t you think? :D ...
Would removing down force not just increase slip angles and not only ware the rubber but (friction) add more heat?
Rear tyres more so, which are where the damage was last week?
It's not exactly that simple, because everything in f1 has 2 dozen inputs, and their all interrelated.

For example you could counteract the the increased slip angle by decreasing camper and increasing the size of the contact patch. Then you tell the drivers easier though the turns because they will be faster on the straits.
But would not decreasing camber increase the surface area in contact with the track and make it worse?
Also put more deflection in the sidewall?
When arguing with a fool, be sure the other person is not doing the same thing.

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dans79
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Re: Mercedes W11

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Big Tea wrote:
Wed Aug 12, 2020 3:50 pm
dans79 wrote:
Wed Aug 12, 2020 3:47 pm
Big Tea wrote:
Wed Aug 12, 2020 3:38 pm


Would removing down force not just increase slip angles and not only ware the rubber but (friction) add more heat?
Rear tyres more so, which are where the damage was last week?
It's not exactly that simple, because everything in f1 has 2 dozen inputs, and their all interrelated.

For example you could counteract the the increased slip angle by decreasing camper and increasing the size of the contact patch. Then you tell the drivers easier though the turns because they will be faster on the straits.
But would not decreasing camber increase the surface area in contact with the track and make it worse?
in simplistic terms increasing the contact patch means more area to do the same amount of work. In other words less energy/heat put into each cm^2 of tread. I say simplistic terms because the size of the contact patch is not constant throughout the lap, as it changes under the varying loads applied to the tire.
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Big Tea
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Re: Mercedes W11

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dans79 wrote:
Wed Aug 12, 2020 3:55 pm
Big Tea wrote:
Wed Aug 12, 2020 3:50 pm
dans79 wrote:
Wed Aug 12, 2020 3:47 pm


It's not exactly that simple, because everything in f1 has 2 dozen inputs, and their all interrelated.

For example you could counteract the the increased slip angle by decreasing camper and increasing the size of the contact patch. Then you tell the drivers easier though the turns because they will be faster on the straits.
But would not decreasing camber increase the surface area in contact with the track and make it worse?
in simplistic terms increasing the contact patch means more area to do the same amount of work. In other words less energy/heat put into each cm^2 of tread. I say simplistic terms because the size of the contact patch is not constant throughout the lap, as it changes under the varying loads applied to the tire.
I was thinking more area more friction surface more heat and 'straighter' side walls steeper angle of load etc? so more deflection creating more heat and more stress??

Not really up to speed on this just speculating.
When arguing with a fool, be sure the other person is not doing the same thing.

Hoffman900
Hoffman900
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Re: Mercedes W11

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Increasing the contact patch increase grip and thus more work is performed.

I can tell you when we got the camber and everything right, our tire temps were always higher (as averaged by the entire tire), and thus pressure rise was higher, because we were making a lot more grip and going faster.

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dans79
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Re: Mercedes W11

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Blistering is a localized phenomena where a small segment of the tread surface is reaching temperatures higher than the compound can withstand. This is usually because that segment of tread surface is doing a disportionate amount of the work.

If you can spread that/load/work/heat out across a larger area of the tires surface you will bring the localized temperature down. The overall tire temperature and pressure might go up, but that's fine as long as you can avoid the blistering.

Here is a good shot of a 2018 Mec tire. Note the heavy blistering is a narrow bnad while the rest of the tire is fine.
Image
Last edited by dans79 on Wed Aug 12, 2020 4:16 pm, edited 1 time in total.
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dans79
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Re: Mercedes W11

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Hoffman900 wrote:
Wed Aug 12, 2020 3:59 pm
Increasing the contact patch increase grip and thus more work is performed.
Yes, but as I mentioned earlier that's where the drivers come in. You tell them to take it easy in the turns, because just because the grip is available doesn't mean they need to use it all. Easy being a relative term, because we are talking about minutiae.
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Hoffman900
Hoffman900
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Re: Mercedes W11

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The tire is rolling over because the sidewall isn't stiff enough for the load it is generating. Decrease grip and you may increase sliding, but you'll minimize the load and deformation. See Darren Heath's photos (scroll with the arrows):



Remember, force alone causes heat, independent of friction (which is a whole other component). This is how glacier move, the overlying weight means the water at the ground / glacier interface doesn't freeze (basal sliding).

A high downforce set up will warm the tires up alone (to some degree) in a straight line independent of cornering.

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dans79
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Re: Mercedes W11

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Hoffman900 wrote:
Wed Aug 12, 2020 4:17 pm
Decrease grip and you may increase sliding, but you'll minimize the load.
True, but that usually leads to graining and that's something the drivers can handle because it normally only lasts for a few laps. Graining can be really bad, but it usually requires a horrendously bad set-up.
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Hoffman900
Hoffman900
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Re: Mercedes W11

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dans79 wrote:
Wed Aug 12, 2020 4:23 pm
Hoffman900 wrote:
Wed Aug 12, 2020 4:17 pm
Decrease grip and you may increase sliding, but you'll minimize the load.
True, but that usually leads to graining and that's something the drivers can handle because it normally only lasts for a few laps. Graining can be really bad, but it usually requires a horrendously bad set-up.
Absolutely.

Another good example of tire chunking is when they ran AMA Superbikes at Daytona (they have since stopped). Rear tires were overheating and coming apart on the banking, not due to slip, but due to the load the banking was allowing the bikes to put into the tire. You can see even the bike tires deform under load