F1 Spar tyre blowouts - how many?

[Eric The Viking]

I know there are a few F1 followers on here, so...

I've just been watching the post GP replays. It looks as though Rosberg had two tyre failures in practice on Friday, not just one. Viewed in slow motion, after the right rear blowout, the left rear also started to deflate before the car left the track, and was thoroughly flat before it came to a stop.

Was it my imagination, or did anyone else spot this? If so, was it the result of debris and/or friction, or are Pirelli pushing their luck?

I'd have expected Vettel to be able to wear the tyres down as far as the canvas (er, Kevlar) before anything catastrophic happened. Losing performance is one thing, a blowout is... well. And three (I think) in one GP weekend?

E.

[edited]P I R E L L I Type Michelin in a hurry, repent at leisure! [/edit]

 

[CHJ]

I think you will find Pirelli make them

this season.


I only saw the one rear failure initially on Rosbergs car, suspect anything else was down to crash forces, side wall pressure in subsequent slide.

 

[NickWelford]

I understand that Pirelli were instructed to develop tyres that would not last a whole race, in order to make pit stops more competitive indeed, it seems they recommended at least two stops. Vettel was pushing his luck, took a risk and it didn't come off. That's the nature of risks, otherwise they wouldn't be risks!

 

[Eric The Viking]

(I have corrected my original post - dunno why I wrote Michelin).

It's unclear from the camera angle available on the BBC site's replay of the Rosberg incident - it may be that the left rear ran over debris (he spun), but it certainly started deflating before the car left the track. In Vettel's case, the tyre seems to have de-laminated - the tread part came away from the inner part. Doesn't seem good/safe.

Monza is another quick track, too...

 

[Harbo]

They official view on Rosberg's - it was caused by a cut?

Vettel was pushing his luck going for a one stop - all others were having 2 or 3.
Pirelli were recommending changing after 12 laps.
The delaminating occurred just after he ran over a kerb at high speed.

Rod

 

[Lons]

I agree and saw no evidence of damage to the other tyre. These drivers are pushing it constantly over the kerbs and Vettel in particular was in the gravel almost every lap in practice. Not good for a tyre with very little rubber #-o

As far as Vettels blowout, you can't blame Pirelli when a tyre is used agressively for longer. You can't blame Vettel either as he told the engineers long before that to think about a pitstop.
Ferrari took a gamble which failed big time and though I'm no fan of Vettel, I feel sorry for him and the spectators as it's all but killed any faint championship hopes he had.

Bob

 

[Racers]

I didn't think they carried spare tyres!


:wink:


Pete

 

[Eric The Viking]

I agree and saw no evidence of damage to the other tyre.

I meant Rosberg's incident. There's a slo-mo of it on the BBC Sport F1 web page. The left rear looks like it is deflating as the car spins to a stop, but the crash barrier obscures the camera position view of the bottom of the wheel at the last moment, so you can't see if it did completely deflate. Also, the Pirelli name is at the bottom of the wheel, and might cause an optical illusion that it's more distorted than it actually is.

If it was going flat, it might have been a debris puncture, but the right rear going might have over-stressed the left rear too. Sideways friction on the tyre alone shouldn't cause deflation - cars spin off all the time without that happening, and, being practice day, Rosberg was on relatively fresh tyres with decent "tread" depth.

These drivers are pushing it constantly over the kerbs and Vettel in particular was in the gravel almost every lap in practice. Not good for a tyre with very little rubber #-o

As far as Vettels blowout, you can't blame Pirelli when a tyre is used agressively for longer. You can't blame Vettel either as he told the engineers long before that to think about a pitstop.
Ferrari took a gamble which failed big time and though I'm no fan of Vettel, I feel sorry for him and the spectators as it's all but killed any faint championship hopes he had.

I'm with Vettel on this, I think: his lap times weren't dropping off, that indicates that the tyre wear, though bad, wasn't of itself taking it close to the limit. According to Andrew Benson (same BBC page):

Vettel also expressed his anger to Paul Hembery after the race, saying that Ferrari had been told they could do 40 laps on the tyre. It failed after 28 laps of that stint in the race.

I agree it's not obvious from the video why Vettel's tyre failed, but you can see debris coming off the tyre just after he exits the right-hander cleanly and gets on the power again, implying it wasn't a straightforward puncture (caused by debris or similar). And in a right hander the right rear is probably less stressed than the other three, and the failure was when the power was applied again.

I know they have tyre pressures in the telemetry stream. I doubt the sample interval is short - probably once per second, or even longer - but if it's more frequent they might learn something from the rate the tyre went down. A puncture would deflate it over several seconds (with the disintegration occurring towards the end of the process), but a catastrophic failure would be practically instantaneous.

It's reasonable that the tyres should be safe for all normal predictable racing risks, including crossing kerbs, because all the drivers do it on every track (to some extent). Of course Pirelli can't guarantee tyre integrity in a collision, nor from contact with debris, but the video clips show no obvious evidence of that in either incident, and if Pirelli are certain Rosberg's tyre was 'cut' they ought to release any data they have supporting that, simply to kill off speculation and put minds at rest. Of course, they may have none -- I couldn't say!

Monza is coming up. Pirelli probably made the tyres for it some while ago, and they'll probably be from the same batch used at Spa. If they have similar incidents there, then I think they have serious questions to answer.

I hope nothing happens though.

E.

PS: I did a bit of Karting in my youth. There's nothing quite like a catastrophic failure of some sort to wreck your confidence (in my case once a chassis weld failed spectacularly). If you collide or crash, you know it's your fault. If the car or the tyres fail you always worry that you're pushing too hard.

 

[Noel]

PS: I did a bit of Karting in my youth. There's nothing quite like a catastrophic failure of some sort to wreck your confidence (in my case once a chassis weld failed spectacularly). If you collide or crash, you know it's your fault. If the car or the tyres fail you always worry that you're pushing too hard.

What class were you in? I did 210 Villiers and 250 Int. Great fun (most of the time).

 

[Eric The Viking]

125cc, Bantam engines mainly.

Zip and Blow frames. It was a Blow frame that came undone - front axle turned the corner but...

You're right though - quite obscenely good fun

 

[n0legs]

I would like to see another manufacturer come back in.
The "tyre wars" were good for various reasons, one which is relevant in this occasion would be identifying construction issues and failure.
If manufacturer A has a few tyre problems at a certain track and manufacturer B doesn't, the cause could probably be more readily identified.
I think in some ways Pirelli have come in for some unfair treatment. The FIA and FOM have supposedly asked them to make tyres that don't last, in an effort to spice things up a bit. I wonder if anyone told the teams to expect this? The teams always seemed surprised by how the tyres perform and react.
Then the teams themselves have decided to do some weird and wonderful set up work, that has pushed the tyres beyond their limits.
In all the time I've been a fan I've never seen such as issue made over tyre pressures, except possibly for the Senna accident.
Rosberg was the luckier of the two on the weekend, he could have had a hell of a bump. Vettels was bad but the tyre, or a good portion of it, stayed on the rim. Either way it's not good for the sport.
Pirelli used to make good cables and joints though :lol:

 

[Lons]

The telling factor in all of this is that teams were talking about a 3 stop strategy and certainly 2 stop was really minimum.

Ferrari took the gamble and it was them who endangered their driver, not Pirelli. Questions were asked in the drivers meeting following the incident with Rosbergs' tyre and bearing that in mind surely commonsense dictates that Ferrari should have been more cautious in common with the other teams. The radio conversation I heard clearly Vettel expected to stop again as he told the team to start thinking about the pit stop, even the sky commentators commented that Vettel was not only driving but managing his engineers as well. :roll:
Despite the outburst by Vettel who understandably spat his dummy out as he'd lost any chance of his faint hopes of a championship, I thought the Pirelli chief was very diplomatic in his response to that outburst.

Roll on Monza (hammer) (hammer)

 

[Eric The Viking]

Obviously, I'm not an expert, but there are effectively two parts to that sort of tyre: the pressure containment and the outer surface in contact with the ground - 'tread' if you will.

Pirelli was asked to make tyres with a tread that wears quickly, degrading performance. That's quite different from a tyre that fails catastrophically because the pressure containment structure fails.

The teams have been told, and we've seen in real life on most circuits, that the expected tyre behaviour is increasingly poor grip after a certain number of laps, reaching the point where the tyre has to be replaced in order for the car to stay competitive.

The sudden failure of tyres, possibly twice at Spa, seems to happen at fast rather than twisty circuits, implying the 'centrifugal force' on the tyre promotes failure at higher speeds, possibly exacerbated by wear (Rosberg's incident being atypical as the tyre wasn't especially old). This isn't what the teams 'signed up' for and it's dangerous.

Is it unfair to wonder how the tyres would last on the older non-hybrid cars of the mid 2000s? OK, Pirelli would probably say they weren't designed for those cars, but would they cope with higher lap speeds if the present technology improves?

I agree: "Roll on Monza"!

E.

 

[woodaxed]

quote from bbc sport

Vettel's tyre exploded on its 29th lap - well within the maximum of 40 laps Pirelli had recommended to Ferrari. The Italian team were also not warned by their Pirelli engineer during that race that they were taking any significant risks.

 

[Lons]

quote from bbc sport

Vettel's tyre exploded on its 29th lap - well within the maximum of 40 laps Pirelli had recommended to Ferrari. The Italian team were also not warned by their Pirelli engineer during that race that they were taking any significant risks.

Not what the Sky "experts" said though and the Pirelli chief said he was "surprised to see" that ferrari cover that number of laps. The consensus before and during the race was a life of around 25 laps max not 40 and to the best of my knowledge Pirelli have denied that they advised Ferrari it was 40 laps. (They said it was an "indicated" life).
If they did then why would any of the teams make more than the obligatory 1 stop to use both compounds in a 44 lap race that was effectively reduced to 43 by the safety car? Doesn't make sense does it! Note that it's mileage and track dynamics that matter not laps and comparisons can be made with other tracks on that basis.
Ferrari boss said a one stop was planned before the race. If that was the case then they didn't tell Vettel as he clearly was expecting to stop as I said it was heard over the radio so surely that's cr*p. (hammer)

29 laps at 7km is more than 200 km covered by that one tyre, at high speed, under heavy breaking and over kerbs and heaven knows how many bits of broken carbon fibre on probably the most demanding track on the F1 circuit. Ferrari say Pirelli ok'd it, Pirelli say not and that they tried a couple of years ago to make a compulsory limit of 50% prime and 30% option race distance which was refused. Ferrari boss has backed down saying he doesn't want a fight - that's a first for Ferrari!

The drivers want and need answers but they were worried before the race so why take the risk? The complainants are Vettel and Rosberg, both wingeing Germans currently on the back foot and Grosjean who always seems involved in something, (he had a great drive in Spa though).
As an aside, I'd take anything the teams, drivers or manufacturers say with a very large pinch of salt. :lol: Both Vettel and Rosberg say they didn't go off the track. My recording of the race must be a different race then. :roll:
I agree with Eric in that the tyres are designed to lose grip and not blow out which is worrying and needs to be investigated fully. Until or even if ever those findings are made public we are all guessing. Hopefully they will get to the bottom of it and sort it out. Monza is another demanding circuit which will be hard on cars and tyres, we don't want any more motor sport deaths!

Bob

Edit:
Everyone on the web has a different opinion but I've just read this one and his analysis makes a lot of sense. The graphs are interesting as well.
http://www.jamesallenonf1.com/2015/08/a ... on-at-spa/

And these: http://www.autosport.com/news/report.php/id/111439
http://www.pressreader.com/south-africa ... 8/TextView
http://www.foxsports.com.au/motor-sport ... 7497699617