Last weekends Belgian Formula One Grand Prix drew headlines after yet another fiasco involving multiple tyre blowouts over the course of the weekend. So, was this latest round of incidents the metaphorical nail in the coffin for these designed-to-degrade tyres? Or has Pirelli worn out their welcome?
During the 2010 season, Bridgestone were the sole tyre supplier for Formula One, and the tyres they allocated for the season were incredible strong, durable and yielded incredible amounts of grip, without much drop off in lap time over the course of a stint. However, despite 2010 being one of the more exciting championship seasons in terms of points, the racing on track was deemed to be not exciting enough as very few overtaking maneuvers occurred, and even fewer pit-stops took place. So, as Bridgestone pulled out of the F1 circus after the 2010 season, the FIA set out a new course of action to spice the racing up by contacting Pirelli and asking if they'd be willing to not only be the sole tyre supplier in Formula One, but design tyres that would wear out more quickly than any other tyre in the sports history. The Italian tyre manufacturer accepted this offer, and in 2011 we got our first taste of tyres that were intentionally designed to wear out in a matter of laps.
The Spa-Francorchamps circuit hosts the Belgian Grand Prix, and presents the highest loading that a Formula One tyre will go through out of any track on the calendar, and in Pirelli's first season, many teams were concerned with the safety of the tyres when many of the cars developed heavy blistering on the inside shoulder of the front tyres. For those of you who may not know what a blister is, a tyre blister is formed when a particular area is super heated due to the speeds and loading that the tyre is subject to, and then the rubber essentially bubbles up and bursts, a bit like a pimple or a blister that you might get on your skin. Teams were strongly advised not to run too low tyre pressures, or too extreme camber angles to try and reduce the chances of a blister-induced tyre failure that weekend, and thankfully, none of the tyres did blow up.
Sebastian Vettel was one of the more vocal drivers on the tyres showing dangerous blistering at the Spa circuit in 2011.
Fast forward two years to the 2013 British Grand Prix, another high loading and high speed track, Pirelli would experience their darkest weekend in the company's history when several drivers had their races ruined after spectacular tyre blowouts, including Lewis Hamilton, Sergio Perez, Jean-Eric Vergne and Felipe Massa. After the race a vast investigation was conducted, and Pirelli apportioned blame to the Silverstone curbing, claiming that the sharp edges were cutting the tyres and leading to structural failures, and to debris on track. They also stated that teams were running tyres in a way that Pirelli did not design the tyres to be run, with extremely low pressures, very negative camber angles and reverse-fitting the tyres onto the wheel rims.
Tyre blowouts are an especially dangerous thing in high-speed Motorsports such as Formula One, not only for the driver with the failed tyre, but for those behind him or her. A race tyre has a metal mesh belted around it for added strength, combined with the rubber itself, and a flying carcass with debris shrapnel exploding into the air is incredibly dangerous for the drivers behind. Fernando Alonso was incredibly lucky not to get injured when Sergio Perez's McLaren tyre blew up on the Hangar Straight, as a shower of carbon fibre and tyre shrapnel hit Alonso as he accelerated towards 300 kph.
2013 was a year where Pirelli designed incredible fragile compounds that would be completely finished after 10 or 15 laps, which meant that races such as Spain saw drivers having to make as many as four or five pit-stops just to get to the end. It also saw a record number of pit-stops with 94 in total for that race. After Silverstone 2013, Pirelli changed the tyre construction back to the 2012-spec, but remained with the 2013 compounds, on the basis of safety.
Lewis Hamilton had his hopes of a home grand prix victory dashed after his left rear blew-up while leading the race.
Which brings us to the 2015 Belgian Grand Prix. Pirelli elected to bring the yellow-marked soft compound and the white-marked medium compound to this years race. The first time they had done so since the 2011 race, amid criticisms that the tyre choices had been too conservative in recent races. This years race saw unusually high temperatures for a region renowned for having common cold snaps with unpredictable rain showers, even in Summer. After the first practice session, most of the teams were concerned with the level of degradation they were seeing, but this could be apportioned to the fact that Pirelli had brought a step-softer set of compounds, combined with the warm conditions and relatively green track surface. Some teams noticed blisters appearing on the inside shoulder of the rear tyres, however a tyre failure probably was not too much of a worry.
About half way through the second Friday practice session, Nico Rosbergs' right rear tyre began to unwind itself on the Kemmel straight. The team were unaware of any tyre pressure drop, so no instruction was given for him to slow down. Approaching Blanchimont at 310 kph, the tyre exploded, leaving Rosberg as a high speed passenger, and he was sent slewing across the track, luckily remaining out of the barriers and avoiding a serious crash. Pirelli spent that night combing the track looking for signs of debris or anything that could lead them to the reason Rosberg's tyre unraveled itself. They concluded on the Saturday morning that Rosberg must have suffered from a cut in the tyre from either a piece of debris, a stone or a sharp edged curb.
Nico Rosberg suffered the first tyre failure of the weekend in spectacular fashion just before the high speed left hander of Blanchimont.
The issue was brought up in the drivers briefing on Saturday night, with many drivers including Rosberg, Vettel and Hamilton speaking up and wanting absolute confidence that this was an isolated incident and would not affect driver safety during the race. Mainly because if you have a tyre failure going through Eau Rouge, that's not a trip back to the pitlane, that's a trip to the hospital.
On the Sunday morning of the Grand Prix, the GP3 support race was marred by a huge crash for Alex Bosak, when he also suffered a tyre failure, only this time he was going through Blanchimont when his front left blew up. Bosak was sent skidding into the barrier, losing a wheel and his entire engine block. The wheel was sent bouncing back across the race track hitting Matt Parry's car, which ended his race and could have easily resulted in a serious injury.
Alex Bosak was unlucky enough to prove that Formula One is not the only category with tyre danger.
With just one lap remaining in the Formula One Grand Prix, being pressured by Romain Grosjean and looking to have successfully completed a one-stop strategy to get him on the final step of the podium, Sebastian Vettel's right rear tyre unraveled itself on the Kemmel Straight, just seconds after exiting Raidillon. Vettel, understandably furious with Pirelli said that "Things like that are not allowed to happen. Full stop. If it happened 200 metres earlier, I am not standing here now."
Immediately after the race, Paul Hembrey was interviewed and quickly concluded that the tyre failure was purely down to general wear, and that Ferrari were trying to run too long on a single set of tyres. They had completed 28 laps up until that point and Vettel and Ferrari both assert that they had been given a maximum tyre life of 40 laps for the Medium compound from Pirelli engineers. However, Pirelli state that teams should not have run the mediums for any more than 22 laps. But now, reports are filtering through that Pirelli has now found more cuts on several other drivers' tyres, but were unable ascertain the exact cause for this.
So, Pirelli are now in a bit of a pickle because they're facing heavy criticism from teams and fans alike, despite designing the tyres that were asked of them by the FIA. However, under no circumstances should a tyre fail after 28 laps, and the fact that it has been so prominent this past weekend points to the structural integrity of the tyres not being up to par for Formula One, or perhaps even GP3. Of course trying to run the tyres too long should make them drop off the "cliff" of grip, but they should never blow up.
With Michelin wanting to re-enter the sport in 2017 and provide larger diameter wheels with rubber that lasts a long time, Pirelli are under increasing pressure to scrap the designed-to-degrade trademark their tyres are becoming known for. However, Pirelli can be heartened by the fact that Bernie Ecclestone is in their corner, primarily because of the track-side sponsorship money they bring to the venues, which is a substantial amount of money.
Pirelli then are not in an enviable position as they are carrying out their requirement of making tyres that wear out, and all they get out of it is a whole load of bad press from F1 teams, drivers and fans about how bad the tyres are. On top of that, people are going into tyre supplier stores and asking for a new set of tyres for their car, "but just not Pirelli's".
Having said that, it's important to note that Pirelli have also been largely responsible for helping to produce many many fantastic grands prix over the past five years, including China and Canada in 2011, Brazil, Abu Dhabi and Valencia in 2012 and Bahrain, Canada and Hungary in 2014. The tyres do, more often than not, make for good viewing of a Formula One grand prix, but being prone to one life-endangering tire failure is one too many.
Being the sole tyre supplier in F1 is no easy task, but when all you get out of it is either invisibility, or bad press, is it really worth staying the course?