Why did a quartet of front-left tyres spectacularly fail in the Qatar GP?

Before arriving in Losail, the engineers from Pirelli and the teams alike expected an enormously demanding Grand Prix on tyres, with the rear-lefts set to endure the greatest loads around the 5.4km clockwise circuit.

Even though the majority of circuits Formula 1 visits are of the same clockwise nature, including the likes of Monaco, Britain, Hungary, Australia and Belgium to name a few, the Losail circuit created yet another outlier of a Grand Prix in a season where anomalous situations entirely uproot expectations.

A quick glance at the track map effectively told you all you needed to know going into the weekend – the track would be monstrously fast. It would exert huge loads through the power units, wings, suspension, tyres and the drivers.

As expected in FP1, FP2 and FP3, the entirely ‘green’ track (no support series’ were present in Losail to clean up the dusty track surface) still produced blisteringly high minimum speeds through the vast majority of the corners. Throughout the weekend the times would only tumble as the desert sand parted, the track rubbered in, and the track limits rules comprehensively changed.

What the engineers didn’t expect was the greater strain seen on the front left in comparison to the rear left, with consistent high speed oversteer in the middle and last sector seemingly dialled out completely for most after a few reconnaissance laps. Whether that was down to the nature of the layout, the track’s surface or because teams focused on dialling in the understeer in their simulators beforehand is a mystery.

There are several explanations

After FP1, Pirelli Boss Mario Isola looked over the fresh data gathered from the tyres that came off a variety of cars up and down the pit lane, and wasn’t expecting what he found.

“The front left was taking a much bigger strain than we expected. At first I thought it must be because the teams were setting their cars up to protect the rear tyres, but when we looked further into it, that wasn’t the case at all.”

“We saw that a big part of it was that there are several corners where you are braking into the turn, so turning in with a lot of combined load on the tyre – longitudinal and lateral. This always takes a lot from the front tyre.”

FP2 would be the only representative session as such before Qualifying with the vast diurnal temperature range of the World’s deserts creating a huge difference in the conditions between day running (FP1 and FP3) and night running (FP2, Qualifying and the Grand Prix). The temperatures wouldn’t have been of any notable influence to the tyre failures, but the way the cars are set up (prioritising cooler temperatures) creates a car which feels different and behaves slightly differently to the optimal FP1 and FP3 car.

Racing under the lights in the more comfortable cooler temperatures is something drivers generally prefer. It also makes it harder to overheat the tyres as long as the track temperature follows the lead of the air temperature.

Both George Russell and Nocholas Latifi’s respective tyre failures occured after 31 laps on the hard compound tyre

Valtteri Bottas, Lando Norris, George Russell and Nicholas Latifi all had their races turned upside down by front-left tyre failures, but with Latifi actually retiring on the spot and the only driver to not make it back to the pits.

Speaking to Sky F1 post-race, Mario Isola remarked that the failures weren’t as dangerous as they seemed because the tyres “lost pressure but in a time that was enough to control the car.” This seemed like a bizarre statement to make, but what it points to is the distinctive type of tyre blowouts seen in Qatar.

Much like at the British Grand Prix at Silverstone last year, the failures were all on the same corner of the car (the front-left). After all Silverstone is a clockwise track like Losail, which also features hugely high speed corners that put a lot of stress through the sidewall of the tyres. The harder compounds of the Pirelli range are normally brought to Silverstone (barring the 2020 70th Anniversary GP) and Pirelli sensibly went down the hard compound route in Qatar too.

Crucially, all four failures happened above the respective stint’s 20 lap mark – 23 laps for Norris’s hards, 31 lap old hards for Russell and Latifi, and 35 lap old mediums for Bottas.

With the exception of the Williams’ pairings failures-in-formation, there were no warnings, no concerns, and no prior consideration of the need to factor in a complete and sudden delamination midway through a stint.

Lando Norris in particular was perplexed as to how a set of hard tyres could last substantially less laps than a used set of softs with more fuel onboard. However Norris managed to make it back to the pits before the tyre fully delaminated after McLaren noticed a small drop in pressure on high alert post-Bottas’s puncture.

Latifi couldn’t make it safely back to the pits without causing a sizeable obstruction, something he sensibly wanted to avoid.

Isola shifted some of the blame away from Pirelli and onto the teams, suggesting that the Pirelli data collected on Friday led to their prediction of a “two-stop strategy.”

“First elements that I can share with you is, all the tyres were quite worn, close to 100 percent. We have cuts on the tyres that we have to understand if they were caused before the loss of pressure or after the loss of pressure.

“We’re waiting for telemetry data from the teams. That is a really important element to understand if the loss of pressure was sudden and the time for that.

“All the drivers were able to go back to the pits, so they lost pressure but in a time that was enough to control the car and to go back to the pits. We’re seeing a lot of impacts at high speed on the kerbs here.

“It’s not a secret that [others] had also damage to chassis, to the floor, to the wings, and when a tyre is worn, it’s less protected from kerbs, big impacts, high-energy impacts. Then it can happen that they start losing pressure, and you have either to change the tyre or you’re flat.”

It’s true the kerbs may have played a big part at Losail, as the track’s flat MotoGP kerbs essentially became part of the circuit itself when the track limits rules were changed to only police limits violations beyond the outer edge of those kerbs. This leads all the drivers directly into the harshly serrated white and green kerbs on the painted concrete behind the flat exit kerbs – the same kerbs that broke Gasly’s front wing and punctured his front-right in Q3.

George Russell pointed to the strength of the DRS creating a scenario where it was impossible to keep cars behind in the race unless you threw caution to the wind.

“The reason for it [the tyre failures] was we just didn’t have enough pace today. In the high speed corners where you need to manage, the corners leading onto the straights, the guys were already right behind me… if I managed any more they would’ve just overtaken regardless.”

“It’s going to happen.”

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: