F1 Decoded: Tyres Explained - Part 1

A deep dive into Formula 1 tyres — from compounds and degradation to the split-second strategy calls that can win or lose a race. Perfect for understanding why rubber, not horsepower, so often decides the chequered flag.

Transcript

SPEAKER_00 0:07

Welcome to F1 Decoded, the podcast that breaks down the world of Formula One from the technology behind the cars to the strategy on race day and the rules for the shape of the sport. We unpack everything that makes F1 tick. Whether you're new to the grid or a longtime fan wanting a clearer view of what's really going on, this is where the sport gets decoded. Today we're looking at all things tires. Let's get going. Welcome to Boxbox Box, your number one F1 podcast for All Things Formula One, or at least if we keep saying it, it might be one day. My name's Scott. Joined today with Mohan. How are you, Mohan? I'm very well, thank you. Mohan, today we're diving into the tires of Formula One and trying to explain them the best we can. What's the reason we're diving into this?

SPEAKER_01 0:55

Um we uh this is a continuation of looking at the technical aspects of Formula One cars and and rules and regulations. Tires play such an integral part of the sport, and there is so much talked about it on a race weekend, for instance, in terms of how it's managed, how the drivers manage them. But we thought it would be useful to break it down a bit further in terms of how they're built, what the rationale behind the choice of tires, and particular key aspects that um form the basis of choice.

SPEAKER_00 1:26

Right, because there have been times in the past with Formula One. Was it Bridgetone where the tires just didn't disintegrate at all and or degrade, and it was quite boring?

SPEAKER_01 1:35

That's right. And um and also there was um the the rules and regulations weren't as tight as they are now, and so teams were taking some license with flexibility of sidewalls and things like that, and actually um FIS clapped on that a lot more and tried to make it fairer and more even in the sport.

SPEAKER_00 1:54

Aaron Powell And I think the other thing too, the removal of mid-race fueling leaves tyres as kind of the only uh moving variable that teams can use to take risks and improve and and whatnot. So you know a lot of effort goes into the tyres and how they operate through Pirelli and and they're made to degrade in a sense, is that right? Absolutely.

SPEAKER_01 2:14

And it actually brings an additional skill that the drivers have to develop over time in terms of how they manage that uh through a race and through a season for that matter, because they all get given the same sets of tires to work with and work within the same constraints of how many changes, minimum changes that they have to do, how the tires are managed between practice days and qualifying and what they're actually allowed to use on race day. So this becomes quite a critical aspect over a weekend of how the teams manage it and how the drivers manage it.

SPEAKER_00 2:48

Right, because if you had a tire that didn't degrade, you you there would be no management required, but certainly that would remove a lot of the entertainment from the sport. So uh it's it's it's all there really for the end product, isn't it? Exactly. And yeah, it's makes for far more interest and far more discussion. Well, let's dive in. So just on the tyre fundamentals and their construction, how are modern F1 tires structurally different from road car tires? Uh especially in carcass construction and sidewall stiffness?

unknown 3:18

Yep.

SPEAKER_01 3:19

So Formula One tires are considered, I guess, an essential structural component of the car, rather than just simply being passive rubber on the bottom of the car. So the carcass itself uses multiple reinforced plies designed to resist deformation under massive uh vertical road. Sometimes that load is over a ton at high speed due to the downforce that is created. So, unlike road tires which absorb bumps and prioritize longevity, Formula One tyres are tuned to provide more predictable deformation so that the aerodynamic services surfaces remain stable. With the move to 18-inch wheels, the sidewall is generally shorter and stiffer than the old 13-inch era, which also changes how the suspension of the car works. Steams now rely more on sort of mechanical suspension components rather than tire flicks or compliance of the tire, but also affects driver feedback in terms of reporting sharper responses within a very narrow operating window. Another difference between Formula One tires and road ties is heat tolerance. Uh, road ties are designed to operate across a wide temperature range, whereas Formula One tires work in a very tight band, usually in the order of a 10 to 15 degree window, uh to maximize grip. Um so this is why engineers treat tyres almost like an aerosurface with predictable behavioral uh behaviors that is controlled a lot more than um uh road ties. So just as an overall comparison, I guess road ties are built to be good enough in every scenario, whereas formula tyres are built to be exceptional in a very narrow scenario.

SPEAKER_00 5:05

So, with that, what role does the tire pressure play in shaping the contact patch and the overall aero platform?

SPEAKER_01 5:14

So, what the management of tyre pressure, it it actually ends up being a hidden setup lever that the teams actually use to fine-tune their performances. So when the pressure increases, the tire becomes more rigid, uh, slightly decreasing ride height, uh, and sort of stabilizing the airflow under the flow of the car, uh, which is quite critical in the ground effect uh cars that was there previously. Um lower temperature expands the contact patch of the tire itself, therefore we've got an improves grip, mechanical grip of the tire, but um it can actually increase uh temperature buildup in the tire. So FIA um dictates minimum tire pressures that have to be in these cars, and teams, as they do with all regulations, push them right to the legal limit. So running pressures that are too low can actually risk structural failure of the tires and lead to blowouts, which has happened in the past. But running it too high can actually sacrifice grip on the track. So the engineers themselves actually have to predict how to manage those pressures over a race. But the other thing they also have to give consideration is how a track actually evolves over a weekend. So as more rubber is laid down on the track, the pressures that are applied to these tires can change over an entire weekend. So these pressure decisions are often revisited several times over a weekend rather than actually having it at a fixed level all the way through.

SPEAKER_00 6:48

And how do the teams balance mechanical grip versus the tire longevity during a stint? And what is mechanical grip for anyone that doesn't know?

SPEAKER_01 6:56

So mechanical grip basically comes from how well the tire itself conforms to the track surface. So if you've got a softer suspension, it allows tires to maintain consistent contact with the track. But too much movement can actually generate heat as well. So what the engineers do is I guess they tune the dampers in the springs to prevent excessive sliding of the car because sliding the tires more than any other wear on the car. From a race perspective, um, teams will sometimes sort of sacrifice lap time uh to ensure that the tire remains within its ideal thermal window, I guess. Um and so what they encourage the drivers to do is to avoid any curb usage or aggressive use of the curves, um, and to reduce any steering lock that they that they would use over over a lap, basically. Um so this there's quite a straight uh trade-off that happens as a result of having to manage those parameters, um, particularly from a strategic point of view, is like do you push early to gain track position uh or do you preserve tires for a late race advantage? And we see this often on race weekends uh where uh drivers that are that are leading the pack at the start of a race uh are doing so at the at the expense of wearing their tires out, and it does um jeopardize them later in a race.

SPEAKER_00 8:26

Yeah, uh I'm interested in the damage caused to the tires across the race. So tell me what actually causes the thermal degradation um and the graining and the blistering and and what's the difference between those and how do drivers feel the difference in the cockpit?

SPEAKER_01 8:41

So, in in basic principles, thermal degradation is basically the chemical breakdown of the rubber as it overheats uh through usage. So what happens is the compound itself loses elasticity and the tyre sort of go gradually goes away, and also breaking distances start increasing. You might see sort of mid-corner fade outs in the tires gripping, um, and it's sort of the traction drops off as time goes on. Uh, graining is usually, I think, like a surface uh phenomenon uh that is caused by a tire that's too cold or being asked to do too much too early. So what happens is the trade surface sort of tears and rolls into small rubber grains that sit on the top of the contact patch of the tyre, uh which as a result of it, because the entire tire then is not on not in contact with the track, it reduces grip. So this creates a certain level of vibration within the car, but also because the entire tyre is not in contact with the track, it actually can create a skating sensation for the driver. So blistering uh sort of tends to originate beneath the surface. Um, if as I mentioned before, if the tire, if the core of the tire gets too hot, uh and sort of certain gases form, and these bubbles can actually lift the rubber uh and create a patchy surface on the tire as such. So what it tends to do, or uh the outcome of all that is that the grip becomes quite unpredictable, um, and drivers have to manage that um or uh risk running wide or running off the track uh during a race. So again, this comes down to how the teams and the drivers manage them strategically. If the blistering risk is increasing, you'll probably find teams pitting a lot earlier to change tire, or they will, over the radio, instruct the driver to reduce the entry speed into corners to manage one of two ways that actually they can manage temperature in these tires.

SPEAKER_00 10:49

Are there are there any other reasons why tyre warm-up is so critical under the current regulations? And uh, are there teams that historically excel at managing that that warm-up period?

SPEAKER_01 11:01

Um, so but the the warm-up is is quite a crucial aspect. And as I mentioned before, these tyres tend to work. The optimal uh working condition is within a very narrow temperature range. And so they can only deliver maximum grip once they reach that specific temperature range. So if you're outside of that, you lose grip, but you're also risking wear on the tire. Cars that generate heat very quickly tends to often do something to do with the geometry of the front of the car and also sort of any energy that is transferred from the brakes themselves. And as a result, I mean this actually meant mean an earlier pit stop than was planned. So we've seen this and it's quite quite a big spectacle when in warm-up laps and formation laps that the drivers try and build temperature up through weaving and braking and managing uh the throttle application on the outlap. But the trick is, I guess, to make sure that you get the thread and the core warmed up at the same time. Overdoing it can uh sort of overheat the surface, but the inside of the tire is actually not warmed up enough. So some drivers and some teams manage this better. I mean, George Russell is, you know, he's called the tire visper for a particular reason and such that if the regulation didn't exist that there's a minimum pitch stop required in a race, you will see some teams that actually can manage an entire race on one set of tires, depending on the trapboard track, obviously, and the weather conditions as well. So it is definitely some teams manage it better than others and know how to get the tires to the optimum temperature, but also go as long as they possibly can for the in the duration of a race.

SPEAKER_00 12:43

Right. So how do how's track surface, ambient temperature, and the energy load affect the the compound selection during a race weekend?

SPEAKER_01 12:54

So every circuit is different, and every circuit, I guess, imposes a different energy profile on these tires. So tracks that actually have got high speed, long duration corners generate a fairly sort of sustained load laterally across the across the tires. Whereas heavy traction zones tend to stress the rear tires a lot more. Big braking zones can actually load the front of the tire and create sort of temperature spikes as such. So the track surface matters quite a bit. And so quite if there is a rough asphalt on the tracks, it can actually obviously translate to wear and tear a lot quicker. The ambient temperature that they're racing or driving in does affect tire wear as well. And it obviously can dictate how quickly temperature is gained or lost in these tires. In hot conditions, sort of the tires can overheat and they can degrade a lot quicker. And in cold conditions, the the skill is to try and keep the temperature of those tires within that that narrow window that we talked about before. Wind can also play a part in that. So how teams actually choose the particular compound that they want to test with, they want to qualify with and race with. So this is like a unified uh expression which which considers how the the circuit and the car are um uh uh encouraging or causing the degradation of a tire.

SPEAKER_00 14:43

So when you're watching when you're watching Formula One and you see the differences in car performance, how much lap time is really coming from tire management?

SPEAKER_01 14:53

So in modern F1 cars, the state of a tire can actually swing lap times by several tenths, which is quite a significant amount. And over a over a race state, the management of tires can actually matter as much as the raw pace of the car itself. So a car that's a tenth slow in clean air can still win if they keep their tires alive, while a fast arrival can actually drop off. So um so teams actually part of their development, they tend to model degradation curves for each of the tires that they are that they use. So um fastest theoretical lap is really the fastest race as such. And and mentioned before, pushing too hard too early can degrade the tires a lot quicker and forcing an extra pit stop, which they wouldn't want to do. It isn't performance, isn't just about peak grip. It basically comes down to how long you can keep the tie in its optimal operating phase. And the winner of a race can often be in who can maintain the tyre in a good enough condition for as long as possible.

SPEAKER_00 16:00

And and why do some cars appear kind on tires while others others are fast but fragile over long runs? Is it is that an illusion and it's got to do with the driver's ability to manage the tires, or has it got to do with the rake of the car, high rake versus low? What's the reason?

SPEAKER_01 16:17

Generally, I guess cars that are considered to be kind on tires tend to have a have a more stable balance setup, I guess, that reduces any sort of sliding that might happen. For instance, if the rear of the car steps out a little on entry of a curve or the front washes out mid-corner, you can create additional slip, and that slip basically equals heat and wear. So the aerodynamic stability plays a massive part in this. So that if the platform is actually consistent through a corner, the driver doesn't have to correct as much as they go through that corner. And so that also translates to being a more uniform loading on the tires itself. So the mechanical compliance of the car matters as well, so that if the setup of a car is too stiff, you can actually have spikes in performance, which directly then translates to the tire and increases the wear and tear on those tires. Some teams, I guess, intentionally design um the setups for sort of a broader operating window so that there are less sort of peaks and troughs in the in their performance, and to try and be more consistent over a race, to I guess to try and one uh a single lap performance is given less value over the longevity of the tire during a race.

SPEAKER_00 17:43

And how do engineers use time modeling and simulation to predict stint length and degradation curves? I suppose you know that's something that we see normally uh before the race. Those things are already predicted. Uh are they predicted by Pirelli? Is that how that that really works?

SPEAKER_01 17:59

Uh it is in a sense, but it's also based on data they have collected, particularly through practice through trials. And it's all there, as you know, there are certain races, certain race weekends where uh teams are encouraged to run certain development tires, shall we say, purely for data collection from someone like Raleigh, which they then use to design these tires for future races or for future seasons. So, what this modeling, I guess, that happens, it combines basic physics so that there's sort of a simulation combined with the telemetry that they that they receive back from these cars. So, sort of the practice, the long runs that they do in practice, use the data collected from that is used a lot. And also they look at how lap times can change as the tires wear down, and what trends the temperature actually has to has a part to play in all of this. So the engineers themselves obviously part of the data collection will input the track temperature, the fuel load, the compound of the tire itself, what traffic the cars are going to be sitting in. And so they put all of this data in into their systems uh to try and come up with the most suitable tire to use on that track in those conditions on that weekend.

SPEAKER_00 19:15

And I mean there's quite loaded questions, uh so like uh impressed you condensing them. How does suspension, you know, suspension geometry, uh, the camber and the the toe settings of the car influence tire wear patterns? I I'd assume, you know, camber obviously changes the contact patch, right?

SPEAKER_01 19:34

That's correct. It basically improves the the cornering grip, shall we say, uh, to try and keep as much of the tire loaded as the car rolls around the corner. So too much camber sort of concentrates the load on the inner shoulder of the car and it sort of causes sort of overheating and faster wear. You can often see this sort of an inage degradation for for cars that have where there's too much camber on the track in that sense. The toe settings themselves can influence sort of the stability of the car, but also how much the tires scrubble on the surface as such. So more tow improves the turning in stability of the car, but at the same time, the compromise that actually increases the drag and and in turn increases the heat that is generated. Very small changes can be made, and each of those changes actually can be quite meaningful of how to manage a particular tire across a stint or over a weekend. So the teams, what they tend to do is uh they run as close to the regulatory limits as they possibly can, but obviously there is a compromise that they that there is consequence in the life of those tires. Um so um the telemetry that we mentioned before, the engine is actually used this to try and pick the optimum conditions, the optimum tire to be used over a weekend.

SPEAKER_00 20:59

Well, how does the ride height impact the tire temperature window, particularly in the ground effect era that we're in? Does that have a lot of is there is there a lot of influence there?

SPEAKER_01 21:09

Uh yeah, these because ground effect cars, I guess they rely on there being stable airflow under the car, under the floor of the car. And so ride height becomes a very sensitive parameter to manage. So mainly because tires under load, the tires compress and they effectively act like a spring. And as the speed increases, the down force increases as well, and the tire deflects, which again can then change the ride height and the performance of the flow. So all of these kind of go hand in hand. Um so if the car actually runs too low, um, so the flow can kind of stall um and the down force can can reduce or drop off if anything else. Um but if you're forcing a correction, you can actually cause the tires to slip as well. So in the in the In the converse situation, if you run uh it too high, you tend to lose efficiency and you tend to lose grip. So either way, sort of the tire behavior feeds back into the aerodynamic behavior of the car. So this is why teams tend to treat the stiffness of a tire and the pressure as part of the aerodynamic setup of the car. So that is uh as the tires heat up, the pressure increases, the stiffness changes, and that could then alter the aerodynamic performance of the car as well. So this is why the teams, I guess, tend to obsess over consistency. So that if particularly if a tie is somewhat unpredictable, uh, or if you're outside the optimal performance window, the car's platform becomes less stable and you can trigger quite a lot of slippage and reduce grip.

SPEAKER_00 22:51

And what compromises the teams make between qualifying performance and race stint tire health? Like is and how are they related? Is it a resource time-based issue where there's a focus on qualifying versus a focus on getting the car right for race day?

SPEAKER_01 23:09

Uh I guess there's different philosophies of how they how they approach each both qualifying and then the race itself. So qualifying, the setups for qualifying are to try and maximize that's that single lap performance. So that the responses have to be sharper, the geometry of the car has to be a lot more aggressive. And settings are developed in a matter that the tire reaches its peak, optimal operating condition as quickly as possible. But what actually happens is that all of those can, because you're trying you're pushing it so hard, can increase degradation if you were to apply the same thing in a race condition. So, and particularly because in a race condition you've got heavier fuel loads to deal with as well. So, what teams tend to do, obviously after qualifying, there are there are restrictions because you you sort of go into park Fermi, and there are very few things that can be changed in park Ferme. So, what they do is they they make any permitted adjustments to try and protect these tires over longer stints. So, what they try and do is try and make sure the back end of the rear end of the car is a little bit calmer, uh any slip that happens on the exit of turns is reduced, and to also maintain a more consistent temperature during the race. So the overall, I guess, is qualifying is about creating peak grip very quickly, but the race is more about trying to keep the tire alive while all the changes are going on around it for the duration of the race.

SPEAKER_00 24:41

Park Ferma should certainly be another episode we um we do in this explain series. What driving techniques help preserve tyres and which habits accelerate uh degradation?

SPEAKER_01 24:52

So um the overall um way that drivers, I guess, try and try and manage um uh tire degradation or preserve the tires, I guess, it's is through smoothness, I guess. And and what they're trying to avoid is to uh any abrupt steering, um, sort of any uh steps at the throttle, um, so or any late corrections that sort of can lead to sort of micro slides of the car, uh which also then spike the temperature of the tire as such. So what the the best time and it is, I guess if you were to look at the data of their driving, you'll find that they're kind of slow in the inputs but fast in the outcomes. So many drivers will prioritize exits and they'll sacrifice entry speed to ensure that the rear tires aren't overloaded for the sake of traction. That is actually quite important in modern cars because uh because the rear temperature tyres can run away very quickly in a race. Brake management becomes a huge part of this. So drivers will actually adjust how the migration of a brake works to minimize any fluctuations in temperature. And they also try and use as much engine braking, I guess, as possible. And that becomes even more important in the hybrid area that we are we are working with currently. So it's not just simply managing tires, it's not just a simple drive slower and you'll be fine kind of scenario. It's controlling where and when the drivers predict any slippage on the track and ensuring that the tire spends as much as possible in that optimum sweet spot temperature conditions throughout the race.

SPEAKER_00 26:37

All right, Mohammed running out of time here. I know you have to go soon, so we'll go rapid fire with these last few questions. Feel free to keep them short. Uh so tell me, how do drivers manage outlaps and inlaps to avoid undercut or overcut vulnerabilities?

SPEAKER_01 26:50

So the outlap is about tire preparation. So too aggressive and you tend to overheat, and too gentle and you arrive at the time lap with the tires well below the operating window. So um so outlap is more about activating the tires, and whereas an inlap is more about exploiting the the conditions of the tire as such. If you can manage both and you can nail both quite well, that translates a lot to track position overall.

SPEAKER_00 27:18

With tire blankets being limited or removed in future regulations, how might driver behavior and race strategy evolve to accommodate this?

SPEAKER_01 27:26

So, as tire blankets are reduced or removed, basically means that the tires will start a lot clock colder after pit stops. And so cold ties, as we know, will have reduced grip and be a lot more prone to sliding. But then also then that translates to graining happening a lot lot earlier in these tires. So sort of removing the blankets has made the tire warm-up a big differentiator in the sport. But it comes down to something, one more responsibility that is put in the driver's hands to manage that that temperature and how the design of the car is changed to influence this as such because of the unpredictability that's going to come out of this.

SPEAKER_00 28:07

It's quite an interesting topic, the tires, Mohan. I I've just thought I'd park it here for a second. We're about to dive into the history of the tires. Would you like to do that in his own episode, I suppose?

SPEAKER_01 28:17

Uh it probably would be worthwhile actually, because there is quite a bit to discuss as part of this. We might do a part two of this, actually.

SPEAKER_00 28:22

Yeah, so I think that's a better idea, actually, because it is it's a it's such a loaded topic. So tell me if we'll wrap up here then. Is there anything else you want to add on the tyres?

SPEAKER_01 28:31

This is an evolving space, and as with every other rule and regulation that the FI has applied, they are learning as they go along. And it's also what is interesting to see is how much teams exploit the the margins that are available. And we'll talk about this in uh in another episode, particularly going back to uh days when there were more than one tire supply on track and all the games that were played, I guess, within the teams, which we which we don't have anymore in terms of uh tire supplies. So um it's a useful, it's a useful history to actually look at, and uh we'll come to that in another episode.

SPEAKER_00 29:06

Yeah, appreciate your time today, Mohan. It's hard to chase the sport that never sleeps, but you know, we we do what we can. So thank you so much for your time. Uh thank you for joining us on this episode of well, this is uh one of our explained episodes, and hopefully if you enjoy these uh these episodes, let us know. There's plenty more of them we're we're looking at doing. Uh, and if you have any suggestions for these, any questions you want to ask uh around these, please reach out and let us know. Let us know what topic you want to hear about, whether that's suspension, whether that's helmets, whether that's uh yeah, whatever it is, you let us know. Um and our socials, Mohan, do you want to throw them out there quickly?

SPEAKER_01 29:42

So our website is uh boxboxbox.net.au, which takes you to our socials on Facebook, Instagram, X, and now TikTok. Uh, please like, subscribe, and send us feedback as well at uh info at boxboxbox.net.au. All feedback is available is welcome given the stage that this podcast is at. And given our current traffic, we promise we will get to it straight away. Absolutely we will.

SPEAKER_00 30:11

Thank you.