Cut Tyres

[Juzh]

SO it once again proves my point that the drivers should be required to drive ON the track...If they cut a tire becuase they want to straightline a corner..too bad..
That said,,,I would have sworn I saw Massa run over somethuing just prior to his tire letting go.

Thankfully, you're in the minority.

[WhiteBlue]

source quoting Anderson report as absolute rubbish

I've been out to look at the kerbs and the reports on sharp edges cutting the tyre side walls are "absolute rubbish". These kerbs have been in since 2009. We've had thousands and thousands of cars go over these kerbs and they have been absolutely fine. We've had them checked by the FIA (International Automobile Federation) and they comply completely.

I think Bernie, the FIA and Pirelli are bringing the sport into disrepute and they need to have a serious look at themselves and change these tyres and not expect all the teams to agree. Take it out of the teams' hands and put safe tyres on these cars. The teams need to look at themselves. They made the decision not to bring a new tyre. I kind of blame Pirelli but they did their best to bring a new tyre to Silverstone and three teams voted against it. Pirelli and Formula One need to have a really good look at themselves and make sure that we have tyres that drivers can drive flat out all the time.

So the BRDC president goes even further to damn Gary Anderson's report. Absolute Rubbish is a hard word but he will know what he is talking about. He has frequently served as FiA "ex driver" steward of F1 meetings.

[bhall]

Easy there, killer. What Gary Anderson says never matters.

[element]

Well, I'm not sure the credibility I should give to this information, but spanish version of Marca newspaper is reporting on their website, citing Mclaren and Sabuer sources, that Pirelli did indeed changed the tyre structure introducing a kevlar strap, while lying to everybody saying they didn't changed anything from Barcelona.

http://www.marca.com/2013/07/01/motor/f ... 72736.html

[WhiteBlue]

http://www.marca.com/2013/07/01/motor/f ... 72736.html
Marca seems to claim that the improved bonding process involved the use of a Kevlar layer which wasn't communicated and should have been. When I look at the pictures of the exploded tyres I must admit that the visible fibres look more like the pale colour of Kevlar than the dark colour of steel that has bonded with rubber. It would mean they tried a hybrid construction from steel and Kevlar. It sounds like a plausible thing and like something Pirelli could have fudged in their communications to appear like a minor change.

[stefan_]

[youtube]http://www.youtube.com/watch?v=6shR0qYWxoc[/youtube]

[garygph]

To me there is an important difference between a delamination problem which they have had
and hence the chat about improved bonding, and the failures we have seen this week end.

where the whole center portion of the tyre tears away from the sidewalls. I seem to remember that when making tyres and different rubber blends the higher the percentage of natural rubber in the blend the better "cut resistance" the tyre had. This may explain why other tyres have not suffered on the same track and kerbs like this one has. One of the other chemicals used is Silica in road cars for supposedly better wet weather grip as well as fuel economy but not cut resistance. I was just wondering if in their quest for wear rates etc they have now have a compound that is not good at all with cut resistance and hence the problems we saw yesterday with this tracks high speed corners really exposing that flaw?

I know we have some tyre experts on this forum and love to know their opinion on this.

Have placed this post on the relevant thread now. Did not realise till now there was already a discussion there.

[element]

5 or 6 identical failures in as ingle race, different from previous ones, are not coincidence. Whatever pirelli introduced in the new bonding didn't worked very well. The kerb talk is rubbish, pirelli has to explain themselves.

[Holm86]

I was also very confused yesterday. Because as I've understood there's no changes to the race tires other than the bonding.
But it was very clearly Kevlar in the tires yesterday. And according to what we've been told so far then they were still steel. So if Pirelli is now deliberately lying then they cant be trusted. They should NOT be extending Pirelli's contract to deliver tires next year IMO.

[Tim.Wright]

But it was very clearly Kevlar in the tires yesterday...

Where did you get that idea from?

[Holm86]

But it was very clearly Kevlar in the tires yesterday...

Where did you get that idea from?

Look at the pictures. The bright yellow'ish fibers coming from the tires. That definitely looks like Kevlar.

[Tim.Wright]

I know what Kevlar looks like. But that top picture of Hamilton was not from this weekend. I see a white fibre in the picture of JEV's tyre bursting. I assume this is just a glass binder or something non structural.

[WhiteBlue]

Marca says its Kevlar on steel, which would be a hybrid. That is consistent with the pictures. You see some fibres that have the typical colour of blackened steel that was bonded with rubber and some that have the whitish colour of Kevlar.

[bhall]

[...]
I was just wondering if in their quest for wear rates etc they have now have a compound that is not good at all with cut resistance and hence the problems we saw yesterday with this tracks high speed corners really exposing that flaw?

[...]

I know jack --- about tires, but I was thinking something along those lines.

I wonder if the revised glue solution compounded Pirelli's problem. When the tires delaminated before - or "punctured," as the company called it - the tread separated cleanly from the carcass, but otherwise left it intact. At Silverstone, the tires exploded. Is it possible that the revised glue solution meant that any failure of the tread caused a failure of the carcass simply because the tread was glued to it "too well"? In other words, when the tread came off, be it due to silly wear or degradation or anything else, did it just take the rest of the tire with it, which caused catastrophic failure in the process?

[beelsebob]

SO it once again proves my point that the drivers should be required to drive ON the track...If they cut a tire becuase they want to straightline a corner..too bad..
That said,,,I would have sworn I saw Massa run over somethuing just prior to his tire letting go.

They do drive on the track. The track is defined as all area in which you can have some part of tyre touching the white line.