Tires in F1
Are tires to blame? Or is it simply the teams pushing the tires too much?
One of the issues that keep coming up in F1 are the tires. The reason for this is obvious to anyone who has watched a race this year, as the commentators and drivers are constantly talking about tire management, and using it as the reason to drive a lot slower during the race.
As an engineer, I am going to just say that yes, they are right. Tires are the number one weak spot in cars today. They are also the main reason we don’t have cars going over 300 mph, as there isn’t a tire rated for that speed and it is due to the forces that have to occur when going that fast, and with that much down force. Formula 1 cars suffer from the same issues, as the down force being applied is huge, especially when going around corners, with the forces visibly distorting the tires.
Now, I am going to say something that will cause people to swear at me: The tires are not the issue. What did I say???? Yes, the tires are not the issue. The issue right now is a combination of two things, namely 1) the down force generated by the cars is too much for the tires to handle, and 2) the time it takes to pit vs the race length is too great.
So, let’s take the first issue, which is the greatest one. Tires are not solid, and they can’t be, so if you load them up too much they will fail, like they did in Silverstone. Their max load is well known, since this is not the first year of use for these tires. There isn’t much Pirelli can do about it, as the teams accepted the tires, and I don’t think they should do anything about it. The teams know the tires, and they have so much data about the tires that they should be able to predict what will happen to them in the race. These failures are simply due to the teams pushing the tires up to and beyond their limits, which the teams know about. Think about the tires being a way to limit the down force the cars can use, which is the same across the board.
Sure, we would love the tires to handle everything thrown at them, and for the teams to race as hard as they can, but due to the down force the teams have added to their cars, they have simply made the tires the weakest link. Yes, the teams are always going to blame the tires, as they just want to apply as much down force as possible. This is why the FIA has imposed a 10% reduction in down force for next year. Some people have brought up using multiple tire manufacturers, but that will simply create another multi-tiered group of teams. Having one manufacturer at least forces all teams to have the same limits, and is about the only standard part that all teams must use.
And this gives us the second problem: The time taken to pit for new tires costs too much time in relation to the length of the race. Having a pit stop take 20 seconds means it simply isn't worth pitting again, as they already need to make one pit stop per race. So, a little math needs to happen here, and yes, I’m using simple numbers to make it easier. Let's just assume that the first pit stop happens at lap 20 of a 55 lap race, which means that the second tire needs to last 35 laps. If they go another 20 laps on the second tire, then pit, that pit stop has cost them 20 seconds, which they need to make up over the last 15 laps, at a rate at 20 sec / 15 laps = 1.34 sec per lap under the time the other guys are lapping. Or they can make the second set of tires go further by slowing down by 20 sec / 35 laps = 0.57 sec per lap over what the other cars which will pit are doing, and not have to worry about overtaking anyone, or having issues in the pits.
Given this, it is not surprising that teams just ask the drivers to manage the tires. But this is a hard issue to solve, as you can’t change the pit lane length or speed, so why not increase the race length to compensate? The cars are going faster anyway, and most races only just last more than 90 minutes. Extending the race is easy to do, and will force another pit stop, which will make the teams push harder to make up the time. They might be able to make a tire last 35 laps, but simply extending the race by 10 more laps would mean the second set would have to go 45 more laps, which isn’t possible for most tires and drivers.
The last thing is to improve the tires. Now this is possible, and is part of the regulation change which they pushed back. The new tires will be bigger at 18” instead of 13”, and have a lower profile, which will also help with reducing the down force issue, as the sidewall will be much thinner, so delaying the new regulations actually didn’t help much in this regard. The teams also didn't want the proposed tires Pirelli came up with, which is why we are using last years version for this year and next year too. I don’t think they have the time to change for next year, but I am looking forward to see what the new tires will do in 2022, and hopefully better racing.