Carlos Sainz Jnr, Toro Rosso, Spa-Francorchamps, 2015

Pirelli urge better track cleaning after Spa blow-outs

2015 Belgian Grand Prix

Posted on

| Written by

Carlos Sainz Jnr, Toro Rosso, Spa-Francorchamps, 2015Pirelli says it will work with the FIA to improve how circuits are cleaned in the wake of the tyre failures seen at the Belgian Grand Prix.

Formula One’s official tyre supplier blamed “an anomalous amount of detritus on the track in Spa” for causing a significant increase in the number of cuts seen in tyres during the race weekend – 63 at Spa compared to an average of 1.2 previously during the season.

“At the end of qualifying on Saturday at Spa, following the exceptional number of cuts noted to the tyres, Pirelli pointed out the condition of the circuit to the FIA and asked for it to be cleaned, as well as for the teams to be told,” said Pirelli in a statement.

“The FIA reacted promptly in arranging for the track to be cleaned and advising the teams. Together with the FIA, Pirelli proposes a study to evaluate the way in which circuits can be cleaned most effectively.”

Pirelli statement in full

Following the recent technical analysis carried out on the tyres used at Spa, Pirelli concludes that:

1)The tests carried out by Pirelli on the tyres used at Spa have confirmed the absence of any structural problems. Pirelli has undertaken in-depth analysis on the materials and production processes used, utilising two different methods of tests and checks.

Microscopic analysis, carried out on a large number of the tyres after the second free practice session, showed no signs of fatigue or integrity issues. The same result was confirmed for the tyres used during the race, which were cross-sectioned and analysed in Milan. Some of the tyres used in the race were subjected to a further laboratory fatigue test, passing all the assessments conclusively and confirming that there was no structural degradation or problem on-track.

Since the start of 2015, 13,748 slick tyres have been used: including on especially severe tracks like Sepang, Barcelona and Silverstone. No problems have ever been discovered, underlining the fundamental solidity of the product.

2)The events of Spa can therefore be put down to external factors, linked with the prolonged use of the tyres on one of the most severe tracks of the championship.

The external factors are demonstrated by a total of 63 cuts found in the tread of the Formula One tyres used over the course of the Spa weekend, following numerous incidents that took place during the support races before the Formula One grand prix. In the previous 15 events (10 races and five test sessions) an average of only 1.2 cuts per event were noted. All this indicates an anomalous amount of detritus on the track in Spa, with a consequent increased risk of encountering a foreign object.

If even a small piece of debris – made of carbon or any other particularly sharp material – penetrates and cuts the various structural parts of a tyre (which is obviously subject to high-speed use, and more susceptible if used for a prolonged period) without penetrating the actual structure, this can cause a failure that is different to that found in the event of a normal puncture, which is characterised by a loss of tyre pressure. And the former was the type of event seen on Sebastian Vettel’s tyre at Spa.

As for Nico Rosberg, in whose case the tyre usage was less, the tyre held up – as the footage clearly shows – and the failure was not instantaneous. For four corners previously, an element of the internal structure of the tyre was visible, coming out of the tread pattern. This highlighted the existence of the damage and the consequent start of the tyre’s attrition.

Throughout the Spa weekend (including practice, qualifying and the race) cuts caused by debris were found on the tyres of other drivers, which damaged the construction but did not cause any failures.

3)At the end of qualifying on Saturday at Spa, following the exceptional number of cuts noted to the tyres, Pirelli pointed out the condition of the circuit to the FIA and asked for it to be cleaned, as well as for the teams to be told. The FIA reacted promptly in arranging for the track to be cleaned and advising the teams.

Together with the FIA, Pirelli proposes a study to evaluate the way in which circuits can be cleaned most effectively.

2015 Belgian Grand Prix

Browse all 2015 Belgian Grand Prix articles

Author information

Keith Collantine
Lifelong motor sport fan Keith set up RaceFans in 2005 - when it was originally called F1 Fanatic. Having previously worked as a motoring...

Got a potential story, tip or enquiry? Find out more about RaceFans and contact us here.

53 comments on “Pirelli urge better track cleaning after Spa blow-outs”

  1. “The track was dirty”.
    Now that’s an original excuse. I admit I didn’t see that coming.

    1. Mercedes had warned their drivers about this and advised them to stay on track as much as possible. So at least for them it wasn’t a surprise. Although Ferrari probably didn’t get the memo or they forgot to tell Vettel

      1. @patrick

        Mercedes had warned their drivers about this and advised them to stay on track as much as possible.

        Have a link saying that?

      2. Can you provide a link to that? Thanks

  2. Presumably Spa gets pretty dirty during the World Endurance Championship’s six-hour long race there. I don’t recall them having any similar tyre failures, but perhaps someone who follows the series more closely can put me right on that?

    1. 22 cars, 4 tyre each, 5 sessions, and 2 failiures, under extreme load. are the WEC cars generate the same load as modern F1 cars, specially in eau rouge? don’t think so. Similiar (like what, 70%?)
      and aren’t you the one who cries about corner cutting? Could it have any impact on the tyre?
      2 flat tyres, and 2 crying drivers, that’s all it was, no need to blow it out of proportion.
      are FIA trying to hide something with pirelli? Please…

      1. Holly cow, reading that gave me headache =/

      2. aren’t you the one who cries about corner cutting?

        I don’t know what about my question apparently deserved such a hostile reply but the answer is ‘no’, both literally and figuratively. I think it’s naive to blame drivers for abusing track limits if the rules or track configurations aren’t there to discourage them from doing so. If it’s quicker to do it and they’re not going to get a penalty, it’s going to happen.

        are FIA trying to hide something with Pirelli? Please…

        I don’t follow you – who’s saying they are?

        22 cars, 4 tyre each, 5 sessions, and 2 failiures

        To be clear, that’s F1, I was asking about the World Endurance Championship. So my question stands.

      3. 2 flat tyres, and 2 crying drivers, that’s all it was, no need to blow it out of proportion.

        It’s proportion is that tyre blow outs present significant safety risks and need to be as uncommon occurrence as possible.

    2. not to mention the carnage that must be found around the Le Sarthe track for the 24h of Le Mans. And isn’t the only difference with previous years that Pirelli chose a softer compound in reaction to criticism that they had become too conservative with tyre choices @keithcollantine?

      I would say that clearly shows that a) the tyres turned out to be just too soft for this track in the warm weather we had, further that b) there is a good safety argument for the FIA to start policing drivers taking it off track constantly (because there lies a huge difference with endurance racing).
      Cleaning the track after a session makes sense, but lets not get into having championship deciding “track sweeping cautions” in F1 during the races!

      WEC cars are heavier, have even more horsepower and somewhat less downforce. Maybe another difference is important, and that is the larger rim size, which makes for quite a different tyre behaviour than F1 tyres with large sidewalls – the fact that quite a high minimum pressure is now mandated would point to that being a significant factor IMO.

      1. But they stay on track so they won’t run through this debris. Which is exactly the difference in that the F1 drivers were seen going off track regularly when the teams had been warned that might damage the tyres.

      2. I believe it is also the case that the tyres used in the WEC are harder than those used in F1, and are designed with a much wider operating window.

        1. Yeh they’re known as racing tyres…

    3. I don’t recall in any motorsport be it WEC, INDY, Monster Trucks, NHRA, NASCAR, Motocross etc, having so many tire issues just as much nor even half as much as F1 has had.

      One can blame F1 because Pirelli is otherwise an amazing tire company, one of the most recognized brands in performance tires. yet I feel they were put under the gun when FOM said “you better give us a better show” and compromised what Pirelli does best – make good tires.

      but maybe Pirelli is at fault also. we look at WEC, INDY, and NASCAR and in no other morotsport from what I can recall, do I see such complaining about tires than in F1. Furthermore if and when a tire has gone down it doesn’t explode in spectacular fashion as it has in F1. One can argue F1 is vastly different in weight, speed, tire dimensions, and tracks used however my point is in no other motorsport do tires I repeat, explode in spectacular fashion as they do in F1 and THAT my friends is the biggest issue I have. maybe Firestone should be contacted; they seem do be doing well in INDY.

      the argument goes in a circle. maybe F1 is by forcing Pirelli to make a better show, are compromising what Pirelli can really do (produce a great tire) or maybe it is indeed Pirelli that just cant come up with a good tire anymore, or lets not forget maybe its the teams who truly abuse the limits of the tires. im not a tire engineer and will never know the details but something sure smells funny…

  3. It’s a pity Hembery rushed out that ‘it was wear’ claim, but even so I’m going to believe Pirelli for now. I can’t help wondering though if there are still different ways a tyre can be made to fail when it gets cut. Steel belt vs kevlar and so on.

    1. They are still saying wear was a factor, Vettels tyre only had 30% tread left, making it much more prone to blow outs from cuts.

  4. I can’t believe that my bicycle’s tires, a pair of Schwalbe Marathon paid 34 € (about 25£), are basically puncture-proof and a Formula 1 Pirelli Zero, which costs a lot more, can be destroyed by a small debris. I think Pirelli has to rethink their tire architecture. Bridgestone and Michelin didn’t explode, they simply went flat.

    1. You don’t drive at 300km/h over sharp carbon fibre pieces with your bicycle though, do you?

      Nor your tires are supposed to degrade after 100km so that we can have more action…

    2. Your bike tyre gets what, about 80kg of load, and tops out at about 30mph?

      It’s also not a designed to degrade showbiz tyre though.

      1. I’m not saying that they are comparable. It’s just a design example. I think there is a design error in Pirellis, you can’t design a F1 tire and completely forget about how to deal with debris on track. Protections from debris doesn’t come from the compound, which is responsible for grip, but from the carcass. I think the issue is the carcass design.

        1. I think the tyre structure has been poor since they changed it for 2012 giving us the stupidly narrow operating temperatures etc. They also seem happy to explain that 95% of the time a front wing hits the sidewall it punctures without ever looking to reduce that, it’s bizarre.
          That said I suspect the issue with the tyres at Spa is their famed inability to deal with vertical and lateral loading simultaneously as it’s the one track that they can’t avoid it.

          1. I think this is the right answer. As no manufacturer using the current structure could build a tire that would be resistant enough.

            Designed to degrade, narrow operational window, resistant.

            Pick two.

    3. F1 tyres are designed to just about hold out for a number of laps. Over engineering the tyres to last multiple race distances would make them heavier and therefor slower.

      1. The compounds might be made to only hold out for a certain number of laps, but the basic structure of the tyre should be engineered for a longer life than that on safety grounds.

  5. Vettel called it when he said that they blame it on debris.

    1. To be fair with Pirelli we saw a lot of corner cutting in Spa. I was sitting at La Source on Saturday and there was a first-lap incident during the GP2 race. I was amazed that the track wasn’t properly cleaned as there were a lot of little pieces of debris remaining off-line so I can’t imagine what it was like off-track. Surely the track was cleaned before Sunday but off-track must contain little pieces swept away from previous sessions. Could someone clarify how they clean the track before a race?

  6. The announcement says that the FIA did clean the track, so either it was new debris or sharp cutting edges that are “fixed” to the track and cannot be cleaned. Intuitively, this has to be the design, construction and, above all, the use of the kerbs.
    Keith was kind enough to post a link to video of previous Francorchamps F1 races (I watched 1995 and 1985) and the obvious difference was that the drivers systematically avoided the kerbs. I’m fairly certain there was less ground clearance beneath the cars, which might partially explain matters.
    This year, it was obvious that the drivers considered the kerbs as a “widening” of the track. Either this should be policed (and I hate regulation) or the kerbs should be made unusable (no lap time gain possible) except in emergency driver safety conditions.

    1. @paul-a

      Intuitively, this has to be the design, construction and, above all, the use of the kerbs.

      Pirelli said nothing about the use of kerbs, though.
      Additionally, some of the kerbs in Spa aren’t even kerbs at all:

      Although this does not have a kerb profile and is essentially just painted race track

    2. The announcement says that the FIA did clean the track, so either it was new debris or sharp cutting edges that are “fixed” to the track and cannot be cleaned.

      At the end of qualifying on Saturday at Spa, following the exceptional number of cuts noted to the tyres, Pirelli pointed out the condition of the circuit to the FIA and asked for it to be cleaned, as well as for the teams to be told. The FIA reacted promptly in arranging for the track to be cleaned and advising the teams.

      The track was cleaned after Qualifying on Saturday. As you can see in the schedule below, there were 3 support races on the morning of the GP with no time for track cleaning prior to its start and Pirelli specifically blames “an anomalous amount of detritus on the track in Spa” “following numerous incidents that took place during the support races before the Formula One grand prix” and says nothing about sharp edges or kerbs.

      SUNDAY SCHEDULE
      08:30-08:45
      FORMULA ONE TRACK INSPECTION AND TRACK TEST
      09:25-10:00
      GP3 SERIES SECOND RACE (13 LAPS OR 30 MINS)
      10:35-11:25
      GP2 SERIES SECOND RACE (18 LAPS OR 45 MINS)
      11:45-12:20
      PORSCHE MOBIL 1 SUPERCUP SECOND RACE (11 LAPS OR 30 MINS)
      12:30
      FORMULA ONE DRIVERS TRACK PARADE
      12:45-13:15
      FORMULA ONE STARTING GRID PRESENTATION
      13:00
      FORMULA ONE MEDICAL INSPECTION
      13:10-13:20
      FORMULA ONE TRACK INSPECTION
      13:30
      FORMULA ONE PIT LANE OPEN
      13:45
      FORMULA ONE PIT LANE CLOSED GRID FORMATION
      13:46
      FORMULA ONE NATIONAL ANTHEM
      14:00-16:00
      FORMULA ONE GRAND PRIX (44 LAPS OR 120 MINS)

      1. There’s plenty of time to clean the track there. I was at the Nurburgring for the 6hr WEC race at the weekend which was as busy and the track was cleaned constantly between races. Marshalls swept all the kerbs and a couple of sweeping trucks went up and down whenever cars were not on track, I wasn’t at Spa but I’d expect the routine to be pretty similar especially if Pirelli pointed out that their tyres were cutting on Friday and Saturday.

        1. Also, Pirelli said the number of cuts “indicates an anomalous amount of detritus”. This is different to saying that there was an unusual amount of debris on track, it’s an assumption that more cuts are due to debris but there’s no proof of it provided.

      2. GP3 had 2 safety cars, GP2 had a VSC (and I think another safety car IIRC), and the Porsches had a safety car too! So there may have

        Interesting about the FIA having to clean the track. They may have swept it after Qualifying, but I was there on the Kemmel straight on Sunday and I don’t recall seeing any of the marshals or any mobile sweepers cleaning the track. Not to say they didn’t elsewhere, but being able to see all the way along the straight from Raidillon to Les Combes you would have thought that some would have been visible, especially as the accidents were mostly at Les Combes.

        Perhaps they should have swept the track whilst the cars were on the grid, awaiting the national anthem.

  7. So Pirelli believe this had absolutely nothing to do with their tyres, not one bit. Who else is shocked?

    1. @john-h you mean the detritus dont you?!

  8. “Debris cut Vettel’s tire, its never our fault” – Paul Hembery

    Called it …

    They should change the name of the company to Debrislli or Pidebris, or maybe stop putting the blame on mysterious debris every time one of their garbage tires explodes without warning.
    Or even better, leave F1 altogether and let someone else do the job, since they obviously can’t do it properly.

    1. @jons
      I think we all did, but credit goes to you for writting it down… ;)

      Pirelli almost always says the same, hard to believe them

  9. Let me sum that statement up:
    1) We believe our product structure is fine as we’ve used 15000 tyres this year and we’ve seen no problems.
    2) See above, must be something other than our tyres and prolonged use of a tyre with a cut in the tread is our best bet.

    They then go on to point out that they found lots of cuts in the tyres across the weekend and detail the different ways we saw tyres fail due to cuts, both explosively but Nico had 4 corners potential warning due to the extra tread he was still carrying.

    My uptake on that is that Pirelli knew tyres were cutting at an alarming rate in comparison to previous events with potential to cause catastrophic failures and decided that the best course of action would be to clean the track before the race. I’m not an expert on this but I’d expect that the track surfaces and corners would be swept quite regularly on race weekends and if there were foreign objects on track they would see similar numbers of cuts/failures in the support races also using Pirellis. The fact that they’ve not mentioned the support races at any time leads me to believe that this is likely an issue specific to F1.

    Which leads me to the question I don’t think they’ve answered sufficiently, why were the tyres cutting so freely and at what point would they consider the track conditions unsafe to run the tyre on?

  10. The claim of an average of 1.2 cuts per-gp before Spa doesn’t go along with what I was told by a Force India engineer about there been over 100 cuts on tyres so far this year.

    And since the guy was right in saying there were over 60 at Spa & some other things I do trust what he was telling me.

    1. @gt-racer Agree.. fortunately there’s no one who’s able to debunk their 1.2 cuts per gp statistic.

    2. those 100+ cuts rather points to about 1.2 cuts PER TEAM per race @gt-racer, indeed quite a difference (10x as much)

      1. That is not what the Pirelli statement says

        The external factors are demonstrated by a total of 63 cuts found in the tread of the Formula One tyres used over the course of the Spa weekend, following numerous incidents that took place during the support races before the Formula One grand prix. In the previous 15 events (10 races and five test sessions) an average of only 1.2 cuts per event were noted.

        Why would they compare 63 cuts (all the teams) at Spa with a figure of an average of 1.2 per event and mean per team? If that is what they mean then then it is poor practice to use statistics in that way, they should not compare a figure from all teams with an average per team.

  11. Maybe we need debris cautions like in NASCAR.

    It will make everything safer, and the racing will be soooooo much more exciting.

    …Nope, couldn’t keep a straight face.

  12. Maybe there are more titanium shards on the track this year, and the Pirelli tyres can only cope with wood splinters. Just saying…! ;)

  13. So it looks the discussion for Pirelli has moved from being “Safer Tires” to “Cleaner Tracks” !!!!!

  14. And with the blame now firmly put on debris, Pirelli should publicly apologize to Ferrari. The comments from Mr. Hembery about Ferrari pushing the tire’s too far, going for an irresponsable strategy, is incorrect according to their own statement.

  15. What will their excuse be for Monza then?

    1. Monza’s easy on the tyres, if anything in previous years teams have found them too hard to build temperature into.

  16. Guybrush Threepwood
    3rd September 2015, 22:04

    I never understood why the marshals don’t have leaf blowers to get rid of the small debris. Organisers pay squillions to host an event and then give the marshals crapy little straw brooms to clean up accidents.

    1. If Bernie had his way, the trackside sprinklers would have washed the track of all the small debris, and we wouldnt have had this problem!

  17. Next they’ll be blaming “leaves on the track” for poor traction, or perhaps “the wrong kind of rain”.

  18. Pirelli says it will work with the FIA to improve how circuits are cleaned in the wake of the tyre failures seen at the Belgian Grand Prix. OR Pirelli could spend more time on producing a less fragile tire!!!! Track cleaners should clean the tracks and Pirelli should make better tires. Thanks, Norris

Leave a Reply

Your email address will not be published. Required fields are marked *

All comments are moderated. See the Comment Policy and FAQ for more.
If the person you're replying to is a registered user you can notify them of your reply using '@username'.