Michelin Withdraws Both Rear Compounds in Argentina after Delamination In FP4

Michelin has taken the highly unusual step of withdrawing not just one, but both rear tire compounds from use at the Termas de Rio Hondo circuit in Argentina. Instead, a different rear tire with a stiffer construction will be issued in the morning, with the teams being given an extra 30-minute session of warm up in which to find a set up for the tires.

The decision was taken after Scott Redding suffered a catastrophic tire delamination with the Pramac Ducati during FP4. The incident happened on a medium rear tire which had been used for just seven laps, according to a statement on the official MotoGP.com website. Redding managed to stay aboard, fortunately, but the rear of his bike was destroyed by a large strip of rubber which had detached itself from the tire. That strip of tire also hit Redding in the back, leaving a massive bruise

The incident caused FP4 to be red-flagged, then, rather bizarrely, restarted once again, before being stopped for a second time. However, it was not immediately clear what had caused Redding's tire to self-destruct, and so the session was allowed to continue, as was qualifying. The reasoning behind allowing the session and QP to continue was that the riders would be doing only short runs, which would not stress the tire for long enough for them to become overheated.

After a meeting between Michelin, Dorna, the safety officers of the FIM, and the teams, it was decided that both rear tires would be withdrawn, as they both used the same construction. Because Michelin will only be able to pinpoint the cause of the failure after careful examination back at their base in Clermont Ferrand, France, they were not confident enough that the problem was only down to the compound, and not the construction.

Instead of the withdrawn tires, a new rear tire will be made available. The new rear features a stiffer construction, which should make it able to withstand stress on the rear better, and will use the medium compound. To allow the riders and teams extra time to find some kind of set up with the new tires, the teams will be given an extra 30-minute session of free practice, due to start at 9am local time, before the warm up sessions start. Warm up will then proceed as normal, with the race happening at the scheduled time of 4pm local time.

This is not the first time Michelin have suffered issues with the tires. Loris Baz suffered a massive blowout at Sepang during the first test, though that was later put down to a combination of low pressure and a foreign object having punctured the tire. It is worth noting that both the Baz and Redding incidents happened at tracks with extreme conditions, to the tallest and heaviest riders on the grid, both riding Ducatis, the most powerful bike on the grid.

It is also worth pointing out that Michelin did not get much of a chance to test in Argentina. The scheduled test slot was struck by poor weather conditions, Michelin and Yamaha test rider Colin Edwards spending much of his time sitting in the garage looking out. At a track like Termas de Rio Hondo, which is both abrasive and very fast, tires are already stressed. The added complication of unusually high temperatures makes life even harder for rear tires.

The one problem which is yet to be addressed is that of the weather. At the time of writing, the weather forecast for Sunday was for it to rain all day, making the extra rear slick excess to requirements. What happens if it is wet in the morning and dry in the afternoon, or wet in the morning and we have a flag-to-flag race remains up in the air.

If that happens, a decision will be taken quite late. It was precisely to handle conditions such as this that Race Direction were given the freedom to adapt the race format and strategy after the problems Bridgestone had at Phillip Island, when a newly resurfaced track was generating more heat in the rear tires than the Japanese tire manufacturer expected. Then, Race Direction shortened the race and instituted a compulsory pit stop halfway through. Clearly, that would remain an option in Argentina.


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... the bikes are too heavy and too powerful.  This places herculean stresses on tyres and places continual pressure on tracks to be slower and have the crowd as far away as possible. 

What would be great would be a smaller, lighter, simpler bike.  Say something about half the capacity of now, to maintain some power they could be an interesting engine design called a two stroke.  This achieves fantastic power with very few parts, so it's light and cheap to produce.  The engine design can be a bit finnicky, so it would also test the riders more.  You could conceivably have a formula with bikes of 115kg easily, or a compromise like 130kg which would reduce the usefulness of exotic materials, making them cheaper still.  These bikes could still produce something in the order of 180hp, so would be spectacular while being much easier on tyres and tracks.

Oh, wait....

Good one... Except MotoGP going 4 stroke actually directly affects road going motorcycles as evidence by the new R1 and 1299. Electronics have been vastly improved making motorcycles safe on the road and more fun to ride especially at the limit at the track. 

LMAO!  that's all I can say due to the avoidance, often considered as taken to extremes, of forms of expression or action that are perceived to exclude, marginalize, or insult groups of people who are socially disadvantaged or discriminated against.

Is Michelin flying those tyres over from France as we speak?  How does that work? 

The rules state that Michelin have to bring an extra spec of tire to cover situations like this. Here, it's an extra hard tire, at Silverstone it might be an extra soft, to cope with very cold mornings. They always have extra tires with them, which they hope won't be needed.

to learn from what happened in testing.  Now they are taking their chances.

Time to own up and face the situation critically now. It does no one any good to try an explain away issues. 

They passed up on going to test here and now put the grid and race at risk.

Now they have the tire pressure sensors. And looking like trying to connect this to certain riders, a specific team or a kind of bike.  How about they go back and figure out how to build margins into these tires and manufacture them better.

It's how Michelin handles this that's important. Problems are to be expected at first.

I don't understand the logic behind the decision to allow fp4 and qualifying to continue.

"The reasoning behind allowing the session and QP to continue was that the riders would be doing only short runs, which would not stress the tire for long enough for them to become overheated."

Scott's tyre delaminated just a few minutes into fp4, it's not like he'd just put a run of 15 laps on it....

So given that the tyre let go after just a few laps, the official statement doesn't hold much water to my mind



This is the PR conundrum any spec tire provider faces.  Get it so right at Qatar that multiple tire combinations are represented on the podium and receive light praise.  Get it wrong in Argentina and face a possible storm of accusations.  Let's give them the benefit of time to work these issues out and provide a safer tire for Sunday hopefully.

I am not an engineer, but it seems almost everything increases at the square of the load/speed etc. The difference in weight between Pedrosa and Redding would not impose a corresponding linear increase in load but rather that value most certainly would be squared. Also the amount of extra power that the Ducati has would be significant. An increase of 10kmh from 340 to 350 takes a lot more power than you would expect. In other words the Ducati is more powerful by more than you think. Maybe some of the engineers amongst you can quantify those values for us. In any case, Michelin do not have an easy job, and having limited time, bikes and riders makes the testing task even more difficult.   

Michelin (or any tire supplier) must work with a narrow but deep performance window. Obviously they are trying to make the tire as light and strong as they can while still maintaining high performance under incredibly stressful conditions, over as long a time as possible. This is why I buy tires from brands that race: They work hard on getting things right!

It was an amazing breakdown. I thought at first the rear frame of the bike had failed, not the tire. It looks as if the entire outer layer of the tire was shed in big chunks all at once. Even the commentators weren't sure if the tire was damaged. The remnant still looked like a slick, only smaller.

It's interesting that, as noted, Baz and Redding are the first two guys to have Rapid Unscheduled Disassembly incidents. They must be just at the edge of the envelope somehow, even if Baz's blowup was attributed to mis-inflation and puncture.

It will be a long night or three in Clermont-Ferrand for somebody. Here's hoping they determine a good solution quickly.

Conditions are interesting as well. The track is FAST, and bikes are spinning and sliding. Just yesterday Redding stated he was enjoying the sideways principle. And he is big, and the bike powerful as ANY BIKE ever to be on track. Relax folks, Michelin are flying by the tire of their pants and it is going ok.

Wait until the weather comes in to play, she may have intermediates out. Anything goes tomorrow, and I am VERY interested in what occurs when the red light goes out. Is everyone is safe? Just enjoy!

Will the stiffer construction tyres (If it doesn't rain) be an advantage to the Honda's?

I would imagine that those tyres would make the bikes slide more like they did in FP1 and FP2 before the track rubbered up.