Thoughts on 2012 tyres?

[amc]

I agree in part with what is being said here. I think the tyres work in far too small a temperature window, meaning that they are difficult to understand and difficult to get working with the correct setup. This, I think, is a flaw with the tyre's design, which probably could have been avoided, and wasn't necessary. Perhaps Pirelli deserve some criticism on that front.

However, some of the criticisms are very harsh. If Pirelli weren't permitted to test the tyres on a 2012-spec car - which is my understanding of the situation - then they can't be expected to accurately predict degradation and wear, and certainly shouldn't be expected to provide reliable and accurate data. That's just not possible. The teams had thousands of miles of running on these tyres in the pre-season to get the data that they wanted, and they ought to have it all.

When they talk about 'understanding the tyres' what they really mean is 'understanding how changes to our car affect the tyres'. That's a challenge that they have also had plently of time to master, and crucially it's the same for everyone. Maybe it's been harder this year, due to having to adapt to new exhausts and all that, but can anyone really argue that the constructors' table doesn't reflect car (and team) performance?

[Jersey Tom]

However, some of the criticisms are very harsh. If Pirelli weren't permitted to test the tyres on a 2012-spec car - which is my understanding of the situation - then they can't be expected to accurately predict degradation and wear, and certainly shouldn't be expected to provide reliable and accurate data. That's just not possible. The teams had thousands of miles of running on these tyres in the pre-season to get the data that they wanted, and they ought to have it all.

Don't agree. I'd say pounding laps on track doesn't really tell you tell you much. A tire is just a component whose performance you have to map out... fundamentally no differently than you have to characterize an engine, damper, spring, antiroll bar, or aero map. You wouldn't do any of those through track testing if you had a choice, and a tire is prob 10x more involved.

You rely on a tire company to supply you specialized data off-track... NOT wear and degradation (you do learn those on the track)... and the impression I get is that the teams don't (or didn't) have enough of that to really have a handle of where their cars would be.

But I could be wrong.

[Cam]

Some will argue "FIA asked Pirelli to make tires like this" and there's a hint of truth to that, but, I generally don't agree with the statement.

Agreed. Your insights into tyre companies being able to provide accurate and valid data to teams is what my expectation would have been. To know you're not getting that would certainly reduce confidence.

I have nothing wrong with burnouts though.

Neither do I! Seeing a NASCAR thrash the rubber and stir the crowd up is what the audience want. The F1 show would be 1000 times better if the driver showed some hint of emotion after winning or getting a great result by turning it on for the hundreds of thousands of loyal fans who've dedicated their time to watch them. Seeing Alonso in Spain rip that F1 beast up in front of that crowd leaving a massive donut and smoke everywhere would have been sweeter than any champaign. But instead, there's so little tyres left on the rim, they have pick up the 'Pirelli marbles' on the way back - if they make it back. Its a disgrace. Whether its regulations or not causing these issues, something has to change. Watching F1 'tippy toe' through a race, then 'tippy toe' back to the pits, scared to be underweight or out of fuel or out of tyres is a fundamental flaw in the sport.

Look at the recent RBR show in NY. Coultard is throwing that thing around all over the place and look at the grin on his face. His joy is what we want to see, that and seeing the very fine RB car thrown around for pure pleasure. I loved it and was left wanting more.

Increase the show - by all means. Start by pandering to the crowd, you might get more people turning up.

[superdread]

Don't agree. I'd say pounding laps on track doesn't really tell you tell you much. A tire is just a component whose performance you have to map out... fundamentally no differently than you have to characterize an engine, damper, spring, antiroll bar, or aero map. You wouldn't do any of those through track testing if you had a choice, and a tire is prob 10x more involved.

You rely on a tire company to supply you specialized data off-track... NOT wear and degradation (you do learn those on the track)... and the impression I get is that the teams don't (or didn't) have enough of that to really have a handle of where their cars would be.

But I could be wrong.

I would reckon the problem with the current generation of tyres is that they are very unstable in a chemical way. The tyre material is some mix of long molecule chains, that is cured to a strong weave.

To get more grip you can make the material softer, so it conforms better to the tiny structures of the asphalt, increasing contact area and therefore friction, this however generally affects the strength of the weave inside the material, so that some materials gets pulled off and stays on the asphalt.

That's not what the Pirellis do, the intermaterial bond seems so weak that lumps get ripped off. I would assume, that the molecule chains are comparatively short (lowering tensile resilience), giving great grip (very soft) but apart from increasing wear also makes the whole thing chemically unstable. Resulting they are more susceptible to the actual temperature (physical properties change more with temperature) and treatment (temperature over time changes structure, high temperature might break up the bonds => tyre disintegrates; or bake the together => less degradation ).

The main cause, I propose, is that Pirelli was asked to produce tyres with very high levels of grip (to counter loss in downforce and power) and a built-in obsolescence, that has forced them into that temperature and treatment sensitive area of chemistry (the examples from other racing series suggests they are doing that for a while).

This is quite speculative, as I have no data (or reference) on the qualitative performance of these tyres, no specific knowledge of tyre rubber chemistry and my chemist in residence is on holiday.

[Richard]

Picking up marbles at the end of the race has always happened even with Bridgetone. If the tyres consisted races with an extra 5 kg of rubber the mechanics would put 5 kg less ballast in the car and drivers would still be asked to pick up marbles.

Out of interest does anyone know how close cars are to the weights limit and how much the marbles add to the finish weight?

As for burnouts, I recall the FIA fine drivers for doing that, although some drivers still do them in front of their home crowds

[Cam]

Fine the driver for a burnout??!! What possible reason would that be for? Heaven forbid we show some excitement.

Take the weight of the car without the tyres? I guess the thinking behind the 2012 tyres to increase the show has lead to downsides of the show as well. Whatever it takes to bring back regular burnouts and a series where tyres aren't the focus.

re: weight of marbles - there was another thread about this - viewtopic.php?f=1&t=10847

hm..I have cleaned a fair share of tyres in my life but I have difficulty to imagine you could add significant weight with the marbles you can collect in a cool down lap.
What you can add is significant ride height when you need to produce a certain amount of it ..but that´s not an issue with F1...

So we got 4 tyres with 660mm diameter and say 355 and 380 maximum width ..that´s roughly 3000cm² of surface area times thickness of accumulated rubber ,say 4mm times specific weight of rubber maybe 1,35 g/cm³ is :1.6Kg added ballast...

maybe the specific weight of the marbles is bigger due to stones embedded ,on the other hand the car will collect only marbles on the inside third with the camber and the need to drive slow to avoid to shed the marbles instantly...
So yes you can possibly add 1Kg of weight doing this funny stuff.It does not cost anything and is good for piece of mind .who would want to get kicked out not having done it...If you can accumulate 3kgs ?who knows.
The teams do not hesitate to rob the drivers of a few litres of fuel and risk having to short shift later in the race and losing positions so I bet they call it VERY close on minimum weight as well...

[marcush.]

thanks for retrieving my hand calculation from back then ... I totally forgot having done that ...but I think it still holds some truth ...



The one thing that totally amazes : We have had certain individuals who seemed to be exceptional with tyre exploitation:
Rosberg as a qualifier and Button as the master of tyre exploitation .
Both have "lost" that edge overnight and seem to be unable to do their thing in every race when all the years before they could at least rely on this strength.
Then we see Perez who drops into the scene..and somehow manages to replicate his tyre saving magic -but not by driving slow and sublimit -he does really throw the car around and can attack still getting more life out of the pirellis..
Experience does not help at all with these tyres ..tyre saving does not help as well as it looks .
Funny a flamboyant style like Hamiltons seems to not adversely affect tyre endurance...

[Richard]

bring back regular burnouts

Where they ever a feature of F1? My point is that burn outs and picking up marbles is not due to Pirelli, that's been teh situation for a long time.

[Jersey Tom]

I would reckon the problem with the current generation of tyres is that they are very unstable in a chemical way. The tyre material is some mix of long molecule chains, that is cured to a strong weave.

To get more grip you can make the material softer, so it conforms better to the tiny structures of the asphalt, increasing contact area and therefore friction, this however generally affects the strength of the weave inside the material, so that some materials gets pulled off and stays on the asphalt.

That's not what the Pirellis do, the intermaterial bond seems so weak that lumps get ripped off. I would assume, that the molecule chains are comparatively short (lowering tensile resilience), giving great grip (very soft) but apart from increasing wear also makes the whole thing chemically unstable. Resulting they are more susceptible to the actual temperature (physical properties change more with temperature) and treatment (temperature over time changes structure, high temperature might break up the bonds => tyre disintegrates; or bake the together => less degradation ).

The main cause, I propose, is that Pirelli was asked to produce tyres with very high levels of grip (to counter loss in downforce and power) and a built-in obsolescence, that has forced them into that temperature and treatment sensitive area of chemistry (the examples from other racing series suggests they are doing that for a while).

This is quite speculative, as I have no data (or reference) on the qualitative performance of these tyres, no specific knowledge of tyre rubber chemistry and my chemist in residence is on holiday.

There are two aspects here, one being the product itself, the other being the level of technical support provided.

The product I think can be described a bit more simply than the above. Comes down to company knowledge / resource / experience. Tire design is all about trade offs. I'll draw up an example here...


No surprise to anyone who has any experience with tires - race tires or consumer. If you want more "grip" with a soft compound, it's going to come at the expense of added heat (generally not a good thing) and/or wear. If you want better wear, you'll be trading off grip or heat. This is why if you go buying tires for your car, you can either get the high mileage warranty tires that aren't particularly sporty... or you can get a sporty summer tire without much tread life. You're stuck in a box and can't get it all.

Then the other dimension is cost and R&D. A company with a lot of resources at its disposal can expand the size of that box. That's the difference between a Bridgestone and a Pirelli, really. For Pirelli to come into F1 and try to have enough grip for the cars to get around (or be anywhere near Bridgestone) it comes at the expense of them disintegrating with terrible wear or durability margin. This is also why I hate the line of "Oh well FIA asked Pirelli to make junk tires to spice up the racing." Just isn't really the case. The experience and development box Pirelli have just does not match Bridgestone, Goodyear, or Michelin who are much larger companies with much more extensive experience. Not to say that Pirelli are idiots or anything, they just don't have the firepower the bigger companies have. Just like comparing Marussia F1 to Ferrari or Red Bull.

Then as I said there's the technical support. Do Pirelli supply the teams with sufficient data for the teams to set their cars up appropriately on any given weekend and know what to expect. The impression I've gotten is no, that's not the case (but I could be wrong). And more to the point, days of track testing really isn't the way to get good data for that - no matter how much instrumentation you have on the car. No different to why you aero testing is done in wind tunnels rather than driving around on air strips or proving grounds. Orders of magnitude more difficult to get consistent precise data in a "live" environment.

[marcush.]

been there ....
the question is ..does the lab data ,which may be perfectly reproduceable -as windtunnel or cfd -give ANY useful help to get more out of the complete package or does it lead to false conclusions.
I fully understand the variables out of your control on track testing are making it incredibly difficult to filter out the noise or is it the other ways round?
You say the circumstances are more important than the characteristics of the product-leads to the conclusion you should not really care about the finer points of tyre understanding as it´s a minor factor in car performance?
Please forgive for offering that joke ..but I could not resist....
I had a similar effect with a strain gauge in an environment of rapid temperature changes .You could not really get useful results from a "normal" strain gauge application -as this was temperature calibrated by using a copper wire -but this was too
slow in reaction for given temperature changes and magnitude and so the data retrieved was just useless crap.Only after getting rid of all the compensation and manually erasing the temperature effects from the data it was possible to get the true force readouts.
My point:if you know your environment and influences you sure can account for those and THEN you will be able to single out the real points of interest....Plus you exactly know the magnitude of influence on the whole system as well.
My feeling is that even in formula 1 people have no real idea what is driving the performance ...at least at times...so they tend to concentrate on areas they either know very well or areas that give them a lot of trouble...(at least they think so)

[Jersey Tom]

I'll say this - by at least a 10-to-1 ratio I'd rather work with "lab" or test rig data for any type of characterization than work purely off of "live environment" data. I'd say that applies to every field I've touched as an engineer, not just tires. That's my opinion and experience.

"Accounting for environmental variables" is a non-trivial task.. and I'd say you can easily get to the point where the correction factors you're trying to chase are bigger than the data itself.

[wunderkind]

I don't know. But all teams knew Pirelli tested their tyres on the 2010 Toyota and I thought it would have been logical, blatantly obvious even, to design the 2012 car that mimicked the ratio of front and rear aero balance and centre of pressure of the 2010 Toyota for an edge in maximizing tyre performance. This point probably evaded most of the teams as they did not realize the difficulty in making the Pirellis work until the second or third pre-season test of the 2012 season. But I thought by the third race of this season, all the teams would have already tried to modify their cars to mimick the 2010 Toyota to get on top of the tyre situation.

[turbof1]

I don't know. But all teams knew Pirelli tested their tyres on the 2010 Toyota and I thought it would have been logical, blatantly obvious even, to design the 2012 car that mimicked the ratio of front and rear aero balance and centre of pressure of the 2010 Toyota for an edge in maximizing tyre performance. This point probably evaded most of the teams as they did not realize the difficulty in making the Pirellis work until the second or third pre-season test of the 2012 season. But I thought by the third race of this season, all the teams would have already tried to modify their cars to mimick the 2010 Toyota to get on top of the tyre situation.

That's impossible. There are a number of either non-mimickable factors or otherwise unknown factors that have an effect on the car:
-2012 downforce levels at the back are lower then the 2010 toyota.
-Nothing is known about the weight distribution of the toyota, while current f1 cars have an almost fixed weight distribution
-There is no data about the suspension. Granted you can roughly get an idea what effect the toyota suspension has on the tyres, but you can never know it precisely
-The toyota was actually designed for Bridgestone tyres and isn't at all suited for pirelli's. mimicking the toyota would be unwise to do.

... Now that I think of it, the 2010 toyota was never used as a pirelli test car. The 2009 car was.

[marcush.]

First of all:a LOT of team personel -including drivers Trulli ,Glock,Kobayashi,Heidfeld,delaRosa,Grosjean have either a quite good insight on the car or the Pirelli development.
I think Toyota guys and Bridgestone guys have been hired by teams.
Along this Toyota have not changed the car much -so all there was available was an adjustment in weight balance and a ballasting the car to rproduce fuelloads /and mandatory weights.
So one can safely assume the Pirelli tyre development was always going into the direction of what a 2009 Toyota would need with 2009 aero and 2010 weightdistribution.So all people involved at one time or another had a very very good chance to know quite a bit more than others..
One might ask him self why LOTUS -formerly known as Renault is going so well...they supply the current testcar and know very well the testhack they supplied -inside out - they had Heidfeld and now have Grosjean who were involved into Tyre development...I think this is more than obvious .
But of course completely off topic .....and has to be moved to the pirelli thread methinks...

[wunderkind]

I don't know. But all teams knew Pirelli tested their tyres on the 2010 Toyota and I thought it would have been logical, blatantly obvious even, to design the 2012 car that mimicked the ratio of front and rear aero balance and centre of pressure of the 2010 Toyota for an edge in maximizing tyre performance. This point probably evaded most of the teams as they did not realize the difficulty in making the Pirellis work until the second or third pre-season test of the 2012 season. But I thought by the third race of this season, all the teams would have already tried to modify their cars to mimick the 2010 Toyota to get on top of the tyre situation.

That's impossible. There are a number of either non-mimickable factors or otherwise unknown factors that have an effect on the car:
-2012 downforce levels at the back are lower then the 2010 toyota.
-Nothing is known about the weight distribution of the toyota, while current f1 cars have an almost fixed weight distribution
-There is no data about the suspension. Granted you can roughly get an idea what effect the toyota suspension has on the tyres, but you can never know it precisely
-The toyota was actually designed for Bridgestone tyres and isn't at all suited for pirelli's. mimicking the toyota would be unwise to do.

... Now that I think of it, the 2010 toyota was never used as a pirelli test car. The 2009 car was.

Yes, I stand corrected, pirelli used the 2009 Toyota to develop the tyres for this season. But I think the critical figures of the testcar such as weight distribution, front and rear downforce were made known to all the teams so they had a good idea of what they were going to work with. Furthermore, teams could have looked at their own data from 2009 to see what they could add to the design of the 2012 package.

The levels of downforce between 2009 and 2012 are different. But I would have thought starting with the aero balance ratio similar to a 2009 Toyota would be a good basis. The 2009 Toyota was designed to run on Bridgestones as you said. But the suspension rules have not changed a great deal since 2009 and as the tyre situation is mostly temperature related, I would think aero load would be the most crucial factor.