So it’s been confirmed - Formula 1 tyres are finally moving to a low profile design
in 2021, which means big rims and skinny tyre walls.
A few other rules around tyres were announced too so let’s have a broad look across the
whole gamut of changes coming in at the start of the next decade.
Firstly, the actual dimensions of the tyres are changing.
Again.
But only slightly.
The front tyres will get a bit narrower again, slimming down from 305 mm wide to just 270
mm.
This isn’t as narrow as the pre 2017 245 mm front tyres but will make the rubber a
little more pliable and easier to warm, which will be part of the balancing act needed with
the reduced sidewalls, as we’ll see in a minute.
The rear tyres will be just as wide at 405 mm but will be a little larger in diameter
increasing from 670 mm to 700, 720 mm across.
This makes them larger in diameter than the front tyres meaning they’ll rotate slightly
slower than the fronts.
A larger diameter rear tyre will, in and of itself, make the rear wheels harder to accelerate
as the torque through the rear axle will be diluted more through the larger radius of
the tyre.
As the force of the tyre on the track is now further away from the turning centre of the
tyre, the force itself if going to be a bit weaker and the power unit will find it slightly
harder to rotate the tyre and drive force into the track.
However it will allow the car to reach a potentially higher top speed as at maximum turning speed,
the tyre travels a longer distance as it has a bigger circumference.
Again, this is all in isolation - facts borne out of just having a larger tyre radius in
and of itself.
In reality, engineers will start adjusting gear ratios and to compensate accordingly.
We should also note that a larger tyre makes for a heavier load and a raised ride height.
But as the construction of the tyre is changing to become proportionally more wheel-focussed,
and suspension will be modified to account for the ride height, we have to wait to see
how these changes bear out.
You’ll notice a lot of ‘the overall effect will not yet be clear’ type chat in this
video as these tyre changes are part of a larger set of rule changes and the way engineers
respond to them as an ensemble package of rules will become clearer over time.
But I’m here to just tell you how each change moves around the goalposts.
So let’s talk low profile tyres, then.
This will be the most obvious change from a visual standpoint.
F1 and its various feeder series has kind of ended up standing along as a breed of racing
cars in continuing with larger profile tyres.
By this, I mean the tyre wall - this length here, remained a pretty large percentage of
the overall tyre/wheel combination across its face.
Indy cars, Formula E, WEC, etc have all gone down the route of slimmer profile tyres, with
the wheel hub taking up a much larger proportion of the tyre.
Even your standard road car has tyre walls much narrower than an F1 car, whose chunky
tyres are much closer to a Land Rover or many other off road, all terrain vehicles.
So F1 tyres will move from 13-ish inch wheels to 18-ish inch wheels meaning they’ll align
with tyres seen not only in other racing series but in most other modern cars.
So firstly, let’s be honest, this means that Pirelli (or whoever gets the contract
(Pirelli)) gets to market their performance tyres more effectively.
Currently when they try and push their P-Zero tyres to Josephine H Bimbleton and her Jaguar
XF there’s a little disconnect their as their road tyres look nothing like their F1
tyres so consumers may rightfully ask, ‘how do these chunky racing tyres prove anything
when it comes to the tyres I want on my car?’
At least now the tyre family is brought closer together and Pirelli can move onto to other
questions like, ‘will the tyres on my BMW estate wear out after 100 km, too, or is that
just an F1 thing?’
I really don’t envy Pirelli sometimes.
Anyway, the knock on effects of taking a good 60 mm off the sidewall are as follows:
Most importantly, it will require an entirely new approach to the suspension systems used
currently by all F1 teams.
And here’s where we briefly side track to suspension:
See, the goal of an F1 car’s suspension systems is to keep the forces through the
tyres balanced and consistent, keeping the car planted and predictable.
I’ll do a full video on suspension soon but, as an overview, note that as the car
rides kerbs, hits bumps and takes corners, the suspension of the car absorbs and rebalances
the forces thrown into the car through the wheels, to stop the car from rolling, lifting
or pitching in such a way that the load on the tyres is reduced, thereby reducing overall
grip and stability.
Drivers want the car to be as balanced and planted as possible when throwing it about.
If, for example, the roll of the car wasn’t properly controlled while moving through a
fast corner, the inside tyres would lose grip and the outside tyres would bear the brunt
of the force.
So here’s where the low profile tyres come back into it.
The kicker is, with the current-day tyres, the sidewall is such a large part of the vertical
height of the tyre that a significant part of the suspension travel is through this squishy
tyre.
So a lot of the absorption of energy from bumps and kerbs and stuff is through the deformation
of the high profile tyre, which I’ve shown here will a massive exaggeration for effect.
This means that currently the suspension systems are set up significantly stiffer than they
otherwise would be and rely on the deformation of the tyre to do a lot of the leg work.
Reducing the profile of the tyre and creating a much stiffer tyre wall would be a radical
change in the suspension behaviour of the car.
Now, there are downsides to the larger profile tyres of course.
This part of the energy absorption is the part of the overall “suspension” that
is out of the control of the team for the most part.
It’s dependant on the design of the tyre and can’t be adjusted.
Furthermore, it dulls a lot of the effect of the car’s actual suspension setup changes,
whereas the lower profile, skinny-walled tyres are much more sensitive to setup changes.
This is a good thing - it means with low profile tyres, engineers can more acutely fine tune
the car’s setup with a greater effect on the car’s performance.
This also leads to a greater variation in setups for a race, knowing the tinkering will
have a more dramatic effect, and not be washed out by the tyres.
Now, with such a dramatic effect on suspension ahead, all the talk now is on whether or not
F1 will allow active suspension systems back into F1.
It’s somewhat expect that, with a high level of software standardisation across the teams,
we’ll see active suspension systems that will allow the car to adjust its stiffness
and response to car movement.
This is a common part of most modern sports cars and most teams have developed systems
that work with their cars that they use for straight line testing.
It’s not particularly controversial but I’ll cover this in detail another time.
The next big change is the banning of tyre warming blankets - a rule change that has
been suggests over and over and very nearly implemented a couple of times over the past
decade.
As we know, tyres are only sufficiently grippy once they reach a certain temperature as the
rubber compound has to become somewhat molten and malleable to adhere to the track.
Before then, at cooler temperatures, the tyres are hard and rigid, a state often referred
to a ‘glassy’.
Therefore, the FIA is demanding a glass-transition temperature - that is the temperature at which
the rubber softens to a grippy condition - to be such that the tyre performs safely straight
out of the pits.
Specifically, the tyre should never be in a glassy state if the air or track temperature
is over 10 degrees Celcius, which is pretty low.
For reference, currently tyres are heated in blankets to keep them at a toasty 80 degrees
Celcius and if they attempted to leave the pits without being pre-heated they’d be
almost completely uncontrollable, unable to get the power down properly and driving like
slicks in the rain.
So banning tyre blankets effectively will be an overall good.
Not only will it save costs and be more energy-conscious it will allow for the development of tyres
that work in a much wider operating window which is both better for racing and more relevant
to, you know, tyres that exist in the real world.
So this is going to be a big change in the compound and construction for 2021 already
and I haven’t even got to the FIA’s magical, semi-enforced tyre characteristic brackets.
So, the FIA have come up with some tyre characteristic brackets - that is, tyre performance and wear
profiles that is expects the 3 race compounds to adhere to across their life.
And, just to make sure we’re all on the same page here: there are 7 compounds of dry
compound tyres but only 3 will be selected for each race.
From 2019, we’re doing away with all the superhard, ultrasoft type labels and just
calling the 3 selected compounds soft, medium and hard, no matter what the actual compound
is.
This is similar to when we used just two compounds and referred to them as prime and option,
depending on which was softer, whichever the actual compound.
So here’s how it’s supposed to work.
The FIA have specified that the designated Hard compound tyre should degrade in such
a way that it gains two seconds in lap time after about 22% race distance.
The Medium tyre should gain 2 seconds time through degradation after just 18% distance,
but should be 1.2 a lap faster than the Hard from the outset.
The Soft compound tyre should degrade to lose 2 seconds after just 10% race distance but
should be about 2.2 seconds quicker than the Hard from the off.
The only specification for how the tyres will continue to degrade after that is that the
FIA want a sudden drop in tyre performance (often referred to as the tyre cliff) to be
engineered into the design.
I am fascinated to know how the FIA expect tyres to be designed to behave within these
tightly-defined parameters.
As good as Pirelli are (and they are really good despite what some may think), we’ve
all seen how hard it’s been for them to get tyres to behave in a way that forces a
simple two stop strategy within the constant changing state of F1 development that continues
to manage tyres more effectively than ever.
If they pull if off, great!
But it sounds like a hell of a challenge to me.
So, we’ve got some big changes ahead for how the cards manage the tyres, their heat,
degradation and their part in the overall suspension.
But bear in mind there are a whole raft of changes coming for 2021 - some technical,
some sporting - and we’ll have to wait for them all to be signed off to begin to speculate
on how these rules will work together and what solutions we’ll expect to see in three
years’ time.
Thanks for watching this video.
I’m going to be doing something extra on these videos for those that watch them through
this channel.
A mini Q&A over the end credits.
So if you want to ask a short question for me to answer at the end of the next video,
leave it in the comments and I’ll pick a few to answer.
They can be about F1, about my opinion or – I don’t know – my cat’s name.
Just anything I can answer briefly!
1) Tohir T asks is I think the massive suite of rule changes for 2021 are about to mess
everything up or will they be good for the sport?
Well we don’t know what they all are yet, but it seems they are taking a long time finalising
them all because they’re trying to get them right.
For example, I think they’re going to scrap most of the power unit changes because half
the reason they were changing everything was to attract new suppliers, but it wasn’t
working so they may as well save money but not changing much at all.
I think minimal changes will allow the field spread to close up and for teams to save money,
but well thought out changes here and there to improve the sport and the show will do
well.
I think these tyre changes are good, for example.
2) Mellcan asks: what are the chances that fuel will become standardised like tyres?
Very low.
The teams have a very complicated relationship with their fuel suppliers as they are often
their oil and lubricant partners too and spend a lot of time working with them on various
parts of the engine and transmission.
They also get a lot of money out of partnering with big name petrochemical brands so I would
expect a lot of push back on such an idea.
3) Franklin asks if I think McLaren would’ve been competitive in 2017 if they’d had the
Renault engine.
No.
More competitive, sure but probably around the levels of Haas and Renault of 2017.
There are some fundamental problems at that team that have been going on for years and
years, but the Honda engine was such a spanner in the works that they couldn’t analyse
the problems.
Thanks everyone.
See you next week.