Pirelli have revealed how the 18-inch wheel and tyre they intend to test at Silverstone tomorrow will look.
Formula One cars currently run on 13-inch tyres, but Pirelli believe a switch to lower-profile rubber will make F1 tyre technology more relevant to road cars.
“The 13-inch tyre is no longer relevant to the everyday road user, because even an 18-inch tyre is used by standard vehicles these days.=,” said Pirelli motorsport director Paul Hembery.
“While 18-inch tyres would be a big step for Formula One, there are many other motorsport series that already use this size. So there’s scope to go even bigger than that in Formula One in years to come.”
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Image © Pirelli
dragoll (@dragoll)
8th July 2014, 12:17
Sex on wheels!
The Blade Runner (@)
8th July 2014, 14:14
Yep, sexy indeed!
Keith Collantine (@keithcollantine)
8th July 2014, 12:18
Definitely looks better than the current 13-inch ones. Hope they’re also quicker.
PorscheF1 (@xtwl)
8th July 2014, 12:23
Agreed.
WilliamB (@william-brierty)
8th July 2014, 13:03
@keithcollantine – I’m fully conscious that it’s childish part of my inner petrolhead that thinks 18in rims on an F1 car looks cooler than 13in (the same part that is obsessed with the Zonda F Roadster), but I really don’t care, because, well…phwoar!!!
Michael Brown (@)
8th July 2014, 14:04
+1 for Zonda being awesome.
BasCB (@bascb)
8th July 2014, 13:10
Agree as well. Looks great.
drmouse (@drmouse)
8th July 2014, 14:04
While I agree they look “cooler”, I quite like the look of the current wheels. They are different.
Also, performance is what we need to know about. I don’t think bolting them on this year’s cars is going to be representative of that. The larger rims and lower profile will bring big changes to the handling. The suspension will need to be altered, and many other aspects of the car changed, to see the true benefit (or otherwise) of the new wheel design.
@HoHum (@hohum)
8th July 2014, 14:28
And more durable.
Jason (@jason12)
8th July 2014, 15:40
Yeah, quicker and durable.
BJ (@beejis60)
8th July 2014, 15:50
@keithcollantine While I agree with you, this will undoubtedly increase costs for the teams by a very very large amount.
Pawel (@marik)
8th July 2014, 18:43
Agreed, I thought it’s going to be ugly,but fortunately, no.
Also if they’ll put these tyres, is there a possibility for the brakes to be bigger? Current brakes are pretty powerful, and I don’t know if bigger ones could be allowed.
Keith Campbell (@keithedin)
9th July 2014, 8:01
@marik They probably could (regulations permitting), but i’m not sure brake size is a limiting factor just now. I think maybe the grip of the tyre on the track surface is what limits braking power (hence lockups when drivers brake harder than the grip level can cope with).
Pawel (@marik)
9th July 2014, 18:43
True, completely forgot about traction.
Sensord4notbeingafanboi (@peartree)
9th July 2014, 4:18
Really? I can’t see how that looks great. I dislike unporportioned racing cars and in many ways these cars with the high and narrow rear wings are odd but this new wheels are very odd to me. I always prefered the rare old Lotus high profile wheels.
James (@iamjamm)
8th July 2014, 12:20
I know it’s only a rendered image, but they look really nice
Alex Ward
8th July 2014, 12:20
Just like in other cars, this is about asthetics, not performance. And i dont like it personally. Its not F1 to me.
regulus (@regulus)
8th July 2014, 12:24
+1
mattshaw85 (@)
8th July 2014, 12:25
erm, no. It does have performance benefits too.
Ben (@)
8th July 2014, 12:28
Not really. A lot of the suspension compliance in current cars is derived from the tire. A lower profile tire will just make engineers adjust the suspension accordingly so that overall compliance will be the same as now.
Looks good to me, though.
mattshaw85 (@)
8th July 2014, 12:40
Surely the ‘give’ that you get from the sidewall when cornering wouldn’t be put back in with suspension adjustments? I would have thought you’d want as little sideways movement as possible.
Ben (@)
8th July 2014, 12:49
Think of it this way: sidewall deformation in cornering has an effect on how engineers determine camber settings (among other things). They already adjust those settings for maximum “grip” and durability results within the window of what tires will allow. Changing the profile of the tire just moves the window; it doesn’t change the net result.
That said, a lack of deformation in cornering could have an effect on aero.
Ben (@)
8th July 2014, 12:57
Actually, ignore the above, because I mangled my response terribly.
For any given tread width and compound, there’s a window for suspension settings like camber, caster, toe, etc, to get the most from a tire. Any change in profile just moves the window for those settings, as long as tread width and compound remain the same.
MazdaChris (@mazdachris)
8th July 2014, 13:11
Its’ not so much about the lateral deformation of the tyres but rather the ‘squash’. When a car is going across the rumble strip for instance, at the moment the tyre is deforming over that surface while the suspension isn’t moving very much. On a car with low profile tyres, it’ll need to have a more pliant suspension setup with a greater range of movement – the tyre can’t deform and remain in contact wiht those kind of bumps, so the suspension needs to do the job instead.
But this isn’t a drawback, it’s a benefit. Springs and dampers are a fairly precise science, and can be controlled to quite a fine degree. Whereas the squash of a tyre is dependent on a large number of factors – tyre pressure, heat, level of wear, and so on. The level of suash and deformation is not a constant; it shifts during the race (and is one of the reasons why different cars seem to work better at different points in the race and during stints). Whereas with a low profile tyre the performance level is pretty constant.
You also do lose that lateral movement, which isn’t desirable since the frequency of the lateral movement isn’t the same as the frequency of the chassis, meaning you can get a sort of disharmony between how the chassis and the tyres load up during cornering. You can end up with a weird backlash against the tyre as the suspension is put under load, which can make the car really unstable and unpredictable while changing direction. Again, this isn’t a constant and it’s not something that’s easy to predict, so it’s pot luck whether or not a car really suffers from this. And again, a low profile minimises this effect, giving a more reliable reaction no matter the application.
BasCB (@bascb)
8th July 2014, 13:12
I would say these tyres should be far easier to model around in simulation because they deform less.
And the smaller deflection should als help with traction and efficiency.
Adam Hardwick (@fluxsource)
8th July 2014, 13:35
@dysthanasiac @bascb The reduced tyre deformation should make the contact patch more consistent (and likewise the aero around the wheel), and also affect the amount of heat they can work into the tyre.
The reduced mass of they tyre itself will also mean that it will probably lose heat quicker, although I’m unsure how this will interact with the now larger wheels and – I presume – brakes.
MazdaChris (@mazdachris)
8th July 2014, 13:42
Another possible consequence might be that if they have to make the suspension more robust with a greater range of motion, you may start to see cars with a lower chassis, to keep the CoG as low as possible. It depends on whether the added weight of the suspension starts to overpower the aerodynamic benefit of having the front of the chassis high up.
Ben (@)
8th July 2014, 13:57
@fluxsource
The increased size of the rim will actually increase unsprung mass, as F1 tire sidewalls are paper thin, and reducing them will have a negligible effect on weight. http://i.imgur.com/qLQSxX2.jpg
As far as getting heat into the tires, its the act of deformation that causes tires to build heat. So, naturally, decreased deformation will tend to make it more difficult to build heat. It’s analogous to the difference between hard and soft compounds. (Pirelli will no doubt use a different compound tomorrow to offset this.)
Again, without an increase in tread width or diameter, the contact won’t change; only the settings teams will use to make the most of it.
I really don’t see a way around the reality that it’s a cosmetic change driven by current trends in consumer tire sales. Folks just tend to prefer buying low-profile tires, and that’s Pirelli’s “road relevance,” I suppose.
@HoHum (@hohum)
8th July 2014, 14:35
The smaller volume of air/nitrogen in the tyres should have less effect on tyre pressure rise with temperature.
Jimbo (@jimbo)
8th July 2014, 15:43
@dysthanasiac – Low profile tyres will reduce unsprung weight which will improve handling.
http://www.formula1-dictionary.net/unsprung_weight.html
Ben (@)
8th July 2014, 16:49
@jimbo
I’m an infrequent commentor here, so my posts are being moderated. In any case, I’ve talked about unsprung mass; it just hasn’t show up yet.
To take a bit of step back, because I initially posted without having my first cup of morning w̶h̶i̶s̶k̶e̶y̶ coffee, here’s what I think:
A tire’s “grip” potential is defined by its compound, contact patch, and generally nothing else. A tire’s contact patch is defined by its tread width, diameter, and nothing else. Since the tire’s outer dimensions will not change with a switch to 18-inch tires, their “grip” potential cannot change without a corresponding change in compound. (This will happen, but I’ll get to that in a moment.)
F1 tires are so thin that reducing the size of the sidewall will have a negligible effect on their weight ( http://i.imgur.com/qLQSxX2.jpg , and keep in mind dry tires are even thinner). But, rim weight will increase appreciably with a low-profile tire, because it will have to be larger. Thus, unsprung mass will actually increase.
I’ve seen in mentioned that low-profile tires will make it easier to maintain tire pressure. While I think the difference is nominal, it’s nonetheless false. Tire pressure relates to gas volume and temperature inside the tire. As much as it will be easier to bring the tires up to pressure because of their reduced volume, it will be that much easier to lose pressure for the same reason. But, again, this won’t really matter so much.
It’s been said that the decreased tire deformation that will result from stiffer sidewalls will make it easier to build heat into the tires. This also isn’t true. Tire deformation itself is what builds heat into tires. Less deformation will then make doing so more difficult. Think of the difference between hard and soft compounds.
Speaking of compounds, and absent suspension settings, which is a rather large topic, if low-profile tires were made with current compounds, they wouldn’t work, because everything I’ve mentioned thus far, and more, has to be taken into account when constructing a tire. Pirelli will have to change compounds in order to successfully switch to low-profile tires.
As we all know, “grip” levels are artificially manipulated by Pirelli according to the wishes of the FIA and others for the sake of dictating performance. I don’t expect that philosophy to change, so I don’t expect Pirelli to change the tire’s performance characteristics when changing construction to accommodate larger rims.
Basically, the only thing I see changing if F1 goes to a low-profile tire is how the tires look, because teams will be left with the same contact patch and compound performance characteristics. They’ll just have to make use of them in a different way: (expensive) suspension changes.
Make sense?
Adam Hardwick (@fluxsource)
8th July 2014, 21:10
@dysthanasiac
I think a disagree with you to an extent regarding the contact patch. While the ideal contact patch will vary only by width and diameter, in reality this is effected by tire deformation as well. When cornering, the inside edge of the tire will “roll” over, increasing the contact, while on the outside edge the tire will tend to lift, reducing it. While these effects are small, they are not insignificant, and additionally play an important part in the pattern of damage through tire use.
I’m not sure who suggested that a stiffer tire will be easier to heat – I just can’t see how someone can come to that conclusion. As to your comment regarding the thinness of the tires meaning the weight difference is negligible – I’ll take your word for it. My initial instinct would be that low profile tires, with lower mass in the tire, would be able to store less energy for a given temperature rise, making it more difficult to keep within the operating window; they’d more difficult to get heat into (as mentioned), but when you do it’s easy to put too much in and overheat them, and they are quicker to cool and drop out of the window. Whether or not this is true I don’t know – I’d need to know a lot more detail about the construction of both tires, and I simply don’t have that info.
Another area that I haven’t seen considered, is punctures. If a car loses a tire, the weird crabbing effect of effectively losing a leg will be reduced, an this may result in differences in damage sustained.
Jimbo (@jimbo)
9th July 2014, 12:06
@dysthanasiac
A tyre’s contact patch is defined by more than diameter and tread width. When a tyre is pressurised it is not perfectly flat across the width and this is compounded when rotating at speed. The contact patch is generally more oval in shape. A lower profile tyre will reduce the effects of deformation due to weight of the car and centrifugal effects when rotating. The slip angle of a low profile tyre under cornering will also be reduced, again improving predictability and handling.
The picture that you show whilst pretty says nothing about the weight of a tyre or the difference between the tread and the side wall. The weight of a tyre is ~9kg for a front and ~11kg for the rear with the hub ~2.5-3kg. Reducing the side wall size of the tyre by 5 inches could reduce weight by more than 2kg whilst increasing the hub size will add ~0.5kg.
As for building heat in the tyre, it is the deformation of the tread that generates the heat required to keep the tyres in their operating window, not the sidewall. As mentioned before, the contact patch will remain more consistent for a lower profile tyre which will lead to more consistent heating across the tyre width reducing uneven wear and graining.
As the tyre will behave more predictably and there will be less undamped elastic motion within the tyre, suspension will become easier to design and control.
Richard Howson
8th July 2014, 13:17
There is a direct performance benefit due to more control of the cars suspension. The current Tyre sidewalls are effectively an un-dampened spring (not of the teams design) which the engineers can only tune directly by changing the Tyre pressure, which in turn has implications in terms of the contact patch for the Tyre. Given the option, any engineer would rather have smaller Tyre sidewalls and then have greater scope for suspension tuning directly via the suspension components which the teams design themselves. Curb riding ability will be much more controllable as will roll during quick changes of direction.
Jake (@jakehardyf1)
8th July 2014, 14:02
Possible less rotational inertia from more magnesium alloy and less tyre rubber.
As simple as it can be, 1/2 mv^2 can be applied to find the angular rotational moment of inertia (again, not the 100% correct way to calculate), but it is close enough.
Anyway, it is weighted towards to angular velocity of the tyre, and with a larger diameter, that will play a role however I predict the reduction in weight will be great enough to compensate for more angular velocity, that in tern is applied to kinetic energy and momentum.
Ben (@)
9th July 2014, 5:29
@fluxsource
And this is where suspension settings come into place. It’s an enormous subject for which I’m not an expert, but I do know enough to know that settings like bound, rebound, jounce, heave, toe, camber, caster, etc affect the contact patch as it relates to wheel rate, roll rate/moment, slip angle, etc. Teams will simply adjust those settings, and redesign components, accordingly.
I know it seems counterintuitive to think that a move from 13-inch to 18-inch tires will have an inconsequential impact on performance, but that’s the case nonetheless. It’s why teams have historically been hesitant to make to change; there’s nothing to gain from it.
Marketing exposure for Pirelli, on the other hand, will change, because people like the way low-profile tires look, and, for whatever reason, they seem to think they work better. Maybe it’s the aggressive appearance.
I really like the way they look, too.
Ben (@)
9th July 2014, 13:00
@jimbo
With all due respect, and I mean that, what you appear to find intuitive about a potential change from 13-inch to 18-inch tires/rims is in conflict with reality. You seem to be thinking of things in static terms, I guess, when they’re just not.
I recommend this, or something like it, if you’re really interested in the subject: http://books.google.com/books?id=JCHDuED3WIkC&printsec=frontcover&dq=Tyre+and+Vehicle+Dynamics&hl=en&sa=X&ei=JS-9U-GsA8nf8gGr7YDoCg&ved=0CC8Q6AEwAA#v=onepage&q=Tyre%20and%20Vehicle%20Dynamics&f=false
Sorry I wasn’t more helpful.
Jimbo (@jimbo)
9th July 2014, 13:37
@dysthanasiac
I was clearly referencing dynamic terms. If you think that changing from 13″ to 18″ rims will have no noticeable difference on tyre dynamics such as contact patch which makes them more resistant to deforming under lateral load resulting in a more predictable and stable contact patch,
then maybe you are the one who need to read the book. Essentially you can get to a higher lateral load before reaching the peak slip angle with lower profile tyres, and that is before getting onto the other subjects of weight savings and more predictable behaviour due to lower rotating mass and more restricted movement of that mass.
Ben (@)
9th July 2014, 14:05
@jimbo
We must be talking past each other, because I’ve not said that tire dynamics won’t change. What I’ve said, or at least have been trying to say, is that the difference in “grip” between a properly tuned suspension with 13-inch tires and a properly tuned suspension with 18-inch tires will be zero. In other words, the variables will change, but the outcome of the equation will be the same.
Correct me where I go wrong, but I’m getting the impression that you’re asserting there will, in fact, be a difference in “grip,” no?
Jimbo (@jimbo)
9th July 2014, 14:29
@dysthanasiac
Yes, there will be a difference in dynamic levels of “grip” that is unrelated to suspension. Would you agree that under a lateral load a lower profile tyre will deform less? Would you also agree that this will lead to a more consistent contact patch?
Ben (@)
9th July 2014, 15:06
@jimbo
Yes, I agree that a low-profile tire will deform less under lateral load. But, that won’t result in more “grip,” because, generally speaking, a suspension tuned properly for that tire, versus one tuned properly for a relatively high-profile tire of the same tread width and diameter, will have decreased wheel rate, roll rate, and camber stiffness in order to avoid overloading the tire and breaking traction. You can only ask so much of a contact path, regardless of its consistency, which, incidentally, should more or less remain the same if the engineer in charge of setup is worth his or her salt. Ignoring those factors will result in substantially less “grip” as well as dramatically increased wear and degradation.
Make sense?
Jimbo (@jimbo)
9th July 2014, 15:21
@dysthanasiac
Suspension settings cannot correct for a deformed contact patch. A more stable contact patch will allow you to get closer to peak slip angles under lateral load. Camber, caster, toe etc can only do so much and is always a trade off to the ideal. Low profile tyres will give one less variable to correct for. If we can’t agree on this then we will have to agree to disagree.
Ben (@)
9th July 2014, 15:38
@jimbo
There’s no such thing as a “deformed contact patch.” This is where your intuition is failing you spectacularly, and you don’t seem to realize it.
And I’m sorry I’ve been unable to help.
Again, check out Pacejka, as he quite literally wrote the book on modern tire design. His theories form the basis from which virtually all tires are now constructed. Until then, yes, let’s agree to disagree.
Jimbo (@jimbo)
9th July 2014, 16:14
http://en.wikipedia.org/wiki/Slip_angle
“If a side-slip velocity u is introduced, the contact patch will be deformed.”
http://books.google.co.uk/books?id=eoy19aWAjBgC&pg=PA367#v=onepage&q&f=false
Section 13.6 covers tyre and contact patch deformation.
http://books.google.co.uk/books?id=NSlSJtEy-NIC&pg=PA54#v=onepage&q&f=false
Section 2.2.1 details some of the physics grip associated with contact patch and how it changes depending on deformation due to slip angle and other forces.
But no, there is not such thing as “deformed contact patch”.
Thank you for your condescending comment.
Ben (@)
9th July 2014, 16:59
@jimbo
I genuinely didn’t mean that condescendingly. I’m sorry it came off that way.
But, I’m glad you’ve glanced through excerpts of the book. A more thorough reading will put things into proper context, and you’ll see that the shape of a tire’s contact patch is largely immaterial as long as it remains the same size. If you could somehow conjure up a contact patch that looks like a five-point star, it would have no impact on “grip” compared to any other contact patch of equal area. (Given the same compound, naturally.)
Think about it: what’s the difference in surface area between a 10m2 square and a 10m2 rectangle? Nothing. (Sorta like: which weighs more, ten pounds of hammers or ten pounds of feathers?)
Bottom line: managing the contact patch of a low-profile tire is no easier or more difficult than doing so with a high-profile tire; it’s just different, but modifying suspension design to accommodate it is expensive. With no reward to be gained in terms of performance, teams have historically balked at making the change.
chris (@9chris9)
8th July 2014, 14:15
+1
i don’t like it, its not f1, its road cars, i can watch btcc for low profile tyres. The high profile acts as suspension and is integral to the performance of the vehicle. I enjoy watching the wheels bounce and wobble when they go over the curbs, they are the one of the only visible working components of the car.
MattDS
8th July 2014, 14:36
But why on earth would you want tyres to act as suspension? Surely the suspension to play it’s role fully and tyres that play less of this role is beneficial to performance.
I like it, a lot.
Banburyhammer (@banburyhammer)
8th July 2014, 15:18
Low profile tyres do provide a net performance benefit however – its why all performance cars and road cars have moved to the huge rims.
The biggest reason being that low profile tyres reduce rolling resistance, and hence improve acceleration and top speed. Essentially the engine will have to do less to power the car and more power is released to further improve performance in both efficiency and ultimate laptime.
The only real issue is the redesign and recalibration of the suspension members, but seeing as the teams have already been through an albeit less radical change from pushrod to pullrod suspension of their own accord, any bleating they do about this is in my opinion farcical. Plus imagine if Michelin decides to come back!
anon
8th July 2014, 18:53
It is not always the case that an increase in tyre diameter yields an improvement in performance – the Top Gear magazine recently carried out a test with the latest generation VW Golf GTi on standard rims and the optional larger rims to assess the impact of the larger rims.
In that instance, they found that the increased compliance of the higher profile tyres not only improved the ride quality, the handling of the car was better on the Top Gear circuit too (to the tune of about a second a lap faster on the standard tyres rather than the larger low profile tyres).
It is about striking a balance on the compliance of the tyres and the effect that has on factors such as the suspension set up – it does not necessarily follow that a larger tyre will automatically improve performance.
In the case of road cars there is an additional incentive in providing larger rims, which is the ability to fit larger brake disks for improved braking performance – after all, if you are tuning a car up to be faster, you generally want to be able to slow it down more quickly as well…
anon
8th July 2014, 18:53
It is not always the case that an increase in tyre diameter yields an improvement in performance – the Top Gear magazine recently carried out a test with the latest generation VW Golf GTi on standard rims and the optional larger rims to assess the impact of the larger rims.
In that instance, they found that the increased compliance of the higher profile tyres not only improved the ride quality, the handling of the car was better on the Top Gear circuit too (to the tune of about a second a lap faster on the standard tyres rather than the larger low profile tyres).
It is about striking a balance on the compliance of the tyres and the effect that has on factors such as the suspension set up – it does not necessarily follow that a larger tyre will automatically improve performance.
In the case of road cars there is an additional incentive in providing larger rims, which is the ability to fit larger brake disks for improved braking performance – after all, if you are tuning a car up to be faster, you generally want to be able to slow it down more quickly as well…
6Speed (@6speed)
8th July 2014, 15:04
+1 yet another change for show rather than go, the suspension changes needed to make these work will be $$$
Jimbo (@jimbo)
8th July 2014, 15:40
No, it is a performance enhancement too. You want to reduce unsprung weight which these tyres will allow:
http://www.formula1-dictionary.net/unsprung_weight.html
NFR
8th July 2014, 16:40
This won’t reduce unsprung weight, as anyone who tracks cars occasionally will tell you that larger wheels actually increase unsprung weight. You are increasing the wheel diameter drastically, which will increase the amount of material it takes to construct the wheel, and therefor increasing weight. Unless they drastically change the composition of the wheel no way that the unsprung weight gets lighter. And F1 wheels are already composed of a magnesium alloy, you really can’t get lighter than that.
From your own link supporting what I wrote “Reducing unsprung weight is the key to improving handling… Note that as the wheel diameter or width increases, the weight of the overall wheel and tire package increases, thereby INCREASING unsprung weight.” May need to reread your source.
Crom
8th July 2014, 18:07
Coulthard commented that the current large sidewall exacerbated Kimi’s accident at the British GP
Sensord4notbeingafanboi (@peartree)
9th July 2014, 4:22
It makes it look very cheap. Like a boy racer’s car. I guess people that like these new wheels also like angel eye specs and listen to listen to van halen whislt tryng to do the split and adjust their make-up.
mateuss (@mateuss)
8th July 2014, 12:23
Yes, to more mechanical grip.
Aqib (@aqibqadeer)
8th July 2014, 12:24
F1 might look beautiful again..these tyres look great