F1's tyre controversy


As the F1 circus prepares for Monza, with the highest speeds of the season, the elephant in the room is that there is still no full explanation for the tyre failures suffered at Spa by Nico Rosberg and Sebastian Vettel.

It may not be a coincidence that both were failures of the right-rear and the problems first became apparent at the same part of track. Vettel’s failed just after the Eau Rouge exit, Rosberg’s held on until just before Blanchimont, but a rearwards-facing camera on his car showed that the carcass began escaping through a hole in the tread a couple of seconds after the exit of Eau Rouge.

That apparent commonality is one factor pointing to damage rather than an inherent failure. The other factor that’s been cited in favour of that explanation is that Spa, being a clockwise circuit, would be expected to place heavier demands on the left-hand tyre than the right. However, that’s not necessarily so.

A tyre engineer not wishing to be named, but who has extensive experience of the demands of the Ardennes track, explained: “Actually, although the circuit is turning right through the lap, the really big load corners – Eau Rouge, Pouhon and Blanchimont – are all lefts and so the total loadings over the lap are actually very similar left-to-right and the peak loadings are bigger on the right. In fact, it wouldn’t be unusual, in my experience, to have a set up with slightly more pressure in the right than in the left.”

So the left-right anomaly is probably a red herring and we’re back to just the similarity between the two failures in where the problems occurred. On the Monday after the race I took a trip up to Eau Rouge to take a look. Below is an image of what I found.

Eau Rouge

This is facing the direction of travel and is the Eau Rouge exit kerb. Pretty much everyone was going with all four wheels beyond the white line and onto the red/yellow painted section. Although this does not have a kerb profile and is essentially just painted race track, you can observe the small ridge at one particular part of it. It’s at a place on the kerb where you would normally be re-joining the track – and the outer edge standing proud by a few millimetres is covered in tyre rubber. Might this imperfection have been enough to critically damage a heavily laterally loaded right-rear tyre as the driver crossed it?

A tyre with a heavily worn tread would be more susceptible to such damage than a less worn one in such a scenario, so Vettel’s unique one-stop strategy could have been a contributory factor. Though that doesn’t apply to Rosberg’s Friday failure, when the tyre had done just 11 laps. Certainly, Vettel’s tyre was still performing well. He was lapping fast and there was no appreciable drop-off. As such, he could not have been out of tread.

If the tyres were damaged by the seam in the track, the question then moves onto whether a racing tyre should be fragile enough that such an imperfection should cause it to blow out?

When Michelin suffered its infamous failures in the 2005 US Grand Prix, it analysed what was causing them, understood it and, realising that it did not have a technical solution immediately at hand, withdrew from the event, giving us a six-car grand prix. It was the only conscientious thing it could do – and it later compensated disappointed race goers.

As Bernie Ecclestone considers the pros and cons of the competing tenders for 2017 and beyond between Pirelli and Michelin, is one of the problems he has with Michelin the fact that it behaved as it did in 2005, rather than adopting ‘the show must go on’ principal?

Had Pirelli done the same after Rosberg’s Friday failure, the Belgian Grand Prix would not have happened. As F1’s promoter and representative of the commercial rights, that would have been a disastrous development for Bernie. Pirelli seems much more compliant towards Bernie’s wishes than Michelin ever was – hence its acquiescence to provide high-degrading tyres that ‘liven up the show’, but which do not allow the drivers to race flat-out.

Which is why the choice of supplier should not be his decision. He is not in a position to make an objective assessment. There are commercial, technical and safety issues in making the choice of supplier. The latter two should not be bent to the requirements of the first.

A strong Grand Prix Drivers’ Association could use the threat of refusing to race until it was satisfied with the explanation for the Spa failures and with what had been put in place to prevent a repetition. But again, commercial pressures are brought to bear on the drivers and the chances of that happening must be seen as remote. The next few days could be very interesting.

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