Mismatched tyres Kovi's problem in China.

[John S]

In this piece taken from ITV-F1, McLaren admit tyre problems for Kovi, could and should this have been avoidable?

It also awnsers the question about Macca pulling the car out of the race.

McLaren revealed that Heikki Kovalainen’s struggle in the opening stint of the Chinese Grand Prix was caused by the fitting of “mismatched tyres” prior to the race.

The Finn was unable to stay ahead of fourth-placed Fernando Alonso on the opening lap, initially passing the Spaniard into turn one before then running wide at turn 13 to give the Renault man the momentum to pass him down the long back straight.

From there he slipped off Alonso's pace before his race hopes later took a further turn for the worse, when first a puncture dropped him out of points contention and then an air pressure problem prompted his retirement on precautionary grounds.

McLaren boss Ron Dennis explained the reason to retire Kovalainen, saying: “Heikki’s first stint was compromised by the fitting of a set of mismatched tyres, which caused his car to understeer,” said team boss Ron Dennis.

“After his first stop, a punctured tyre then forced an unscheduled pit stop before an air pressure problem with his engine caused us to retire him in order to avoid risking an engine failure."

Had Kovalainen completed the race and then subsequently been forced into an engine change one race earlier than scheduled for Brazil, he would have picked up a 10-place grid drop in Interlagos

[Steven Roy]

I still need someone to tell me what that means.  What is a mis-matched set of tyres?

I have seen this story repeated in so many news sites and no-one has provided an explanation.  So either this is something that everyone but me knows about or these sites are thoughtlesses repeating anything they hear.

[Dare]

Do they have left and right side tires in F1?Or
maybe they mixed some rain tires with soft
tires or maybe Alonso messed with the wrong
car in his bid to help Massa

[Scott]

I don't know about right or left (but it figures that one side would take more g's than the other when going around an essentially circular circuit), but they surely change at least the pressures between front and rear depending on the car setup and conditions.  Maybe they were simply inflated incorrectly.  Like you though, I thought with the current rules, all 4 tires were the same design in F1.  Either McLaren has just come up with a new excuse so their rivals don't know what the real problem was, or they should explain further what a mis-matched set of tires really is.

[Steven Roy]

The tyres are all marked left or right.  I assume that they are uni-directional.

[Alianora La Canta]

I don't understand how you can mis-match tyres without the FIA punishing the team for either mixing up the sets or not having a homogenous compound on the tyres.

[Steven Roy]

If it was mixed compounds it would stand out like a sore thumb because either one would have a stripe or one would not.

[John S]

The only thing I can think of is a tyre that has covered quite a distance somehow got paired with a tyre that had just been scrubbed.

Particularly if the more used tyre was put on the wheel that takes most load, or have I got that bit wrong and it's the other way round?

[greener_09]

What ever the problem was with the tyres i cant believe a team like mcclaren would make a mistake like that. It has most likely cost them the constructors championship and surely someone is looking for another job for letting it happen.

[Ian]

If Ferrari can forget(?)and only bring our three wheels for Irvine surely anything is possible.

[Steven Roy]

F1 is such a presured environment that its history is littered with examples of the best teams making he dumbest mistakes.  I can never remember the driver so I will guess. At Spa a few years ago Williams left Ralf on jacks with no wheels on the car as everyone left on the parade lap.  They jacked him up to change wheels and simply ran out of time.  Not as bad as Ferrari only having 3 wheels for Irvine at one pit stop in 1999(?).  When the guy turned up with the fourth wheel they decided to have a committee meeting before they put it on.

Things like this have happened to everyone.

THe idea of tyres on different mileages is the most feasible explanation I have heard so far.  Presumbaly someone mixed two sets of tyres so there must be another mismatched set in the garage somewhere.

[Scott]

I remember - except whether or not it was Spa.  It was Ralf, but the wheels were on, he was just sitting on the jacks while everyone else pulled away.  Serious red faces at Williams.

[Alianora La Canta]

It was Ralf Schumacher, Spa 2001, third start. He was fine for the first start, but that got cancelled because Heinz-Harald Frentzen stalled. There was no time to change tyres before the second start, which resulted in the race being red-flagged due to Irvine and Burti colliding. By the time the tyre wall had been rebuilt enough for Burti to be helped from the car, there had been plenty of time to change tyres. Unfortunately "plenty" wasn't enough time for Williams because they couldn't make their mind up what the weather was going to do (a perennial problem at Spa).

[Steven Roy]

Thanks Ali.

I had forgotten that it the the race where Burti went burrowing under the tyre wall.

[Warmwater]

I don't know if this applies to FF1 or not, but when I was on the pit crew of a stock car series many years ago, we would carefully measure every tire every way possible. The most important was the circumference, and every tire was slightly different, even varying from one side to the other. Since we mostly raced on ovals, we would fit the largest tires on the outside and the smaller on the inside which would help the car turn. Thus we had matched sets of tires. The drivers claimed to be able to tell the difference, but at the time I thought it was a bit silly.
I am sure that FF1 teams check their tires even more carefully and match them according to several characteristics.
Just a thought...some of you racers out there will have more up-to-date ideas about this.