PIRELLI 2020/2021 Tyre Thread

[izzy]

I think the tyre design should allow both single stop and two stop to be equally effective. Ie you can go medium-hard or soft-soft-medium and have the same total race elapsed time.

Isn't this missing the idea? The shortest elapsed time should be achieved by being the best team, engineering, strategy and driving. That was the beauty of Hungary, that the team did loads of analysis, as James explains , and combined with Lewis that produced a faster race time not the same race time.

No, I fear you miss my point. The tyre strategy should give equal time thus the team and driver need to make the difference. This was the case in Hungary because the combination of Hamilton and car was able to make it work. Other drivers / cars wouldn't have done so. But it would be nice if they could. That gives options and thus variability which leads to interest and thus happy fans.

Oh, okay perhaps I was taking you too literally, that if they gave the same time it wouldn't make any difference which strategy they chose. But being close does mean some teams will chose each strategy and then we get to see them play out, totally agree. And if you read that James article he does emphasise quite a lot that their plan, after a lot of analysis, involved pressuring Max into going through his tyres too fast.

It was F1 on several levels at once, which I love, and these tyres were a big part of it and personally i wouldn't change them, apart from making them 18"

[Just_a_fan]

I'm no fan of changing to 18inch rims. It's purely a visual thing and won't improve the racing. It's the tyre equivalent of the swept front wing.

[TimW]

F1 just needs tyres that can be pushed for their entire stint, and which don't benefit or hamper any team. The tyres shouldn't decide the outcome, in other words.

Building a car that utilises the tyres well is part of F1.

Problem that I see with current tires is that they only suit high downforce cars. You really need to be on the extreme of the low drag vs high downforce spectrum for them to work. I think it would become more interesting if a concept where you sacrifice cornering speed for top speed would stand a chance. Now it doesn't because the tires are not suitable for it.

[izzy]

I'm no fan of changing to 18inch rims. It's purely a visual thing and won't improve the racing. It's the tyre equivalent of the swept front wing.

It's much better engineering, you wouldn't have 13" wheels on your road car would you? Floppy undamped things being half the suspension.

[Just_a_fan]

I'm no fan of changing to 18inch rims. It's purely a visual thing and won't improve the racing. It's the tyre equivalent of the swept front wing.

It's much better engineering, you wouldn't have 13" wheels on your road car would you? Floppy undamped things being half the suspension.

On most road cars, 17, 18, 19, 20 inch rims (and larger, of course) are for aesthetic purposes only. On road cars, putting short sidewall tyres on makes the ride awful, increases tramlining, causes premature damage to suspension components etc. There is no reason other than visual style / fashion. Some cars have large brakes and they require larger wheels to fit over them, but that tends to be fast sports cars or heavy SUVs. Even then, the sidewall doesn't need to be rubber band small. My Range Rover Sport, for example has 19 or 20 inch wheels. I have 19 inch fitted with 55 aspect tyres where the standard is 50 aspect. The 20 inch comes with 40 aspect ratio. That's ridiculous on something weighing 2.5 - 3 tonnes. On the 55 ratio tyres, it'll still make very rapid progress along a winding bit of road - certainly much quicker than the speed limit. Why the need to run shorter sidewalls? Indeed, I'd run smaller wheels if I could, but the brakes limit the size to 19 inch minimum (18inch rims are available aftermarket that are designed to fit over the brakes but they're not very common).

My first GTi had 205/55 tyres on 15 inch wheels. That was fast enough cross country to be very illegal and rode well on bad tarmac too. Modern stuff sits on 40 or even 35 aspect ratio. So the suspension is very firm, the ride awful, they're actually often slower along bad roads than "slower" cars on realistic sidewalls.

F1 cars lap faster than any other car - including those on short sidewall tyres. So tyre sidewall isn't an issue in lap time.

We'll get short sidewall F1 tyres but it's only for fashion reasons - to look "modern", "sporty" etc.

[izzy]

On most road cars, 17, 18, 19, 20 inch rims (and larger, of course) are for aesthetic purposes only. On road cars, putting short sidewall tyres on makes the ride awful, increases tramlining, causes premature damage to suspension components etc. There is no reason other than visual style / fashion. Some cars have large brakes and they require larger wheels to fit over them, but that tends to be fast sports cars or heavy SUVs. Even then, the sidewall doesn't need to be rubber band small. My Range Rover Sport, for example has 19 or 20 inch wheels. I have 19 inch fitted with 55 aspect tyres where the standard is 50 aspect. The 20 inch comes with 40 aspect ratio. That's ridiculous on something weighing 2.5 - 3 tonnes. On the 55 ratio tyres, it'll still make very rapid progress along a winding bit of road - certainly much quicker than the speed limit. Why the need to run shorter sidewalls? Indeed, I'd run smaller wheels if I could, but the brakes limit the size to 19 inch minimum (18inch rims are available aftermarket that are designed to fit over the brakes but they're not very common).

My first GTi had 205/55 tyres on 15 inch wheels. That was fast enough cross country to be very illegal and rode well on bad tarmac too. Modern stuff sits on 40 or even 35 aspect ratio. So the suspension is very firm, the ride awful, they're actually often slower along bad roads than "slower" cars on realistic sidewalls.

F1 cars lap faster than any other car - including those on short sidewall tyres. So tyre sidewall isn't an issue in lap time.

We'll get short sidewall F1 tyres but it's only for fashion reasons - to look "modern", "sporty" etc.

Hey my dad's 135i has 35% rears!!! Till he changed them anyway. And the ride is not bad with its electronic dampers on Comfort. But seriously, a sidewall has so little lateral stiffness you want it as short as possible, so that when you rotate the road wheel inside you have as little lag and movement as possible before the tread area rotates on the road. And then you want the lateral load that generates transferred back to the wheel as fast and directly as possible too.

The 18" wheels for F1 will make the cars feel a lot less heavy, much sharper and more responsive. Much more of the suspension travel will be properly managed with rigid geometry and damping. It's quite weird at the moment watching them squirm around bouncing and shuddering from side to side while the car floats around on top, when the rest of the car is engineered so awesomely.

[roon]

Thermal management and suspension control should improve. Seems like a win-win. How they fill in the barrel is my question. Do the brakes increase in diameter? Or stay the same size. Brake duct volume will increase i.e. brake duct development will increase. There will suddenly be ~6cm free space between the wheel barrel and the edge of the brake disc, if the the discs remain the same size. That will be filled with carbon fiber vanes and ducts, maybe taller heat sinks.

F1 cars lap faster than any other car - including those on short sidewall tyres.

But not because of tall sidewalls. There are a hundred other variables. 919 Evo lapped faster around spa than an F1 car, on short sidewall tires. Not because of fashion, but due to regulations and engineering trends. Prototype racing has used short sidewalls for at least three decades.

[DiogoBrand]

I'm no fan of changing to 18inch rims. It's purely a visual thing and won't improve the racing. It's the tyre equivalent of the swept front wing.

It is definitely not just for aesthetic reasons, in fact I bet most fans will hate the look of the wheels at first, but in my opinion they have two benefits:
Give the engineers more control over suspension travel. While now most of the suspension work is done by tyres you can't set up the way you want, lower sidewalls will do the opposite.
Bring that aspect of F1 to the 21st century. Every other racing series, and even road cars have gone above 13 inch wheels for decades now. The only two reasons F1 didn't was because at first they used that to limit brake size, and later they didn't change it just because they were afraid it would look weird. I'd much rather have wheels that look weird at first than wheels from 1970.

[roon]

If the rules allowed, the teams would probably lay up their own wheels of various interesting designs.

[SiLo]

imagine if teams could run 13, 15, 17, or 18" wheels depending on what they felt was best.

[JordanMugen]

On most road cars, 17, 18, 19, 20 inch rims (and larger, of course) are for aesthetic purposes only.

A 20" wheel with 35 profile tyre like on the Civic Type R increases handling precision greatly, that is why it is chosen.

It means the dampers, and geometry can be responsible for the handling, instead of uncontrolled motions in the tyre. Ride comfort is said to still be excellent for a hot hatch type car.

[Maritimer]

Bigger wheels also allow for bigger brakes, which is the main reason new cars no longer come with 13" wheels.

[Just_a_fan]

On most road cars, 17, 18, 19, 20 inch rims (and larger, of course) are for aesthetic purposes only.

A 20" wheel with 35 profile tyre like on the Civic Type R increases handling precision greatly, that is why it is chosen.

It means the dampers, and geometry can be responsible for the handling, instead of uncontrolled motions in the tyre. Ride comfort is said to still be excellent for a hot hatch type car.

Having followed modern hatches on ultra low profile tyres, the "handling precision" is used to avoid pot holes and other imperfections. It certainly isn't needed to drive along public roads at even dangerously high speeds. Ergo, it isn't necessary for a road car and is just marketing drivel.

I've owned hot hatches and driven them, er, youthfully , and the best have been those that absorb the surface imperfections, not fight them. That needs compliance, not "precision".

My 2.5 tonne SUV on 19 inch, 55 profile tyres, will hustle down a road at indecent speed and a lovely ride.

[JordanMugen]

Having followed modern hatches on ultra low profile tyres, the "handling precision" is used to avoid pot holes and other imperfections. It certainly isn't needed to drive along public roads at even dangerously high speeds.

My 2.5 tonne SUV on 19 inch, 55 profile tyres, will hustle down a road at indecent speed and a lovely ride.

Civic Type R handles the rather bumpy Nordschleife public toll road just fine: https://youtu.be/QYV3yWshHLI?t=109 Hustling comfortably at 245 km/hr, and easily taking sweepers at 185 km/hr.

Does your SUV really provide the same level of enjoyable handling precision in either 185 km/hr sweepers, 60 km/hr hairpins and everything in between, as afforded by the 35 profile tyres?

I made the mistake myself of replacing the factory 225/40 R18 tyres on factory 18x7.5" rims of an earlier model Civic Type R, with 225/50 R16 tyres on Mazda RX7 16x8" rims thinking the smoother ride of the 50 profile tyres would have no handling drawbacks.

I was sadly mistaken, as it was very much like driving on balloons. The high profile tyres produced a lot of unwanted movement and even increased body roll, as the tyres contribute to the overall spring rate. The 16" wheels had to go, as this was totally unacceptable.

[henry]

I switch between low and not low profile every winter and spring. On the day it feels a little different. After that I don’t really notice. I was surprised on the first couple of occasions having imagined bigger differences. The suspension is tuned for the low profile summer tyres. For the straightforward driving I do day to day the steering precision and pothole riding are fine with both. As an aside in snow and ice the winter tyres are quite extraordinary. I wish I had known for some of my earlier, more unruly, cars.

Racing is an entirely different business. I suspect that the engineers will find handling curbs on the exit of corners will be more difficult with lower profile rear tyres. I think that the choice of a slightly larger tread diameter at the rear will have been heavily influenced by this.