"A foolish consistency is the hobgoblin of little minds," wrote the American poet and philosopher Ralph Waldo Emerson. Little minds or no, consistency is the one complaint which many riders still level at Michelin, the official tire supplier of MotoGP. When it comes to grip, feedback, and chatter, complaints are few and far between. But consistency of feel between one tire and another remains a problem, at least in the minds of the riders.
The 2018 season opener at Qatar threw up several more examples of this lack of consistency. Ahead of the weekend, Cal Crutchlow had expressed concerns about the variation between what are supposed to be identical tires. "You can show them the data, and if you have 20% throttle here, and this tire's got this much more spin than the tire that you've got 50% throttle, and that's got less spin. It doesn't work. Apparently, they've come off the same batch."
During the race, both Johann Zarco and Dani Pedrosa believed that a lack of consistency had hampered their performance. Zarco had led for the first 17 laps, before fading with what he believed was a faulty front tire. "I got the best I could, I did what I could do, I did the job, and when I have a technician from Michelin and also on my team saying that something has been wrong, it means that OK, the rider's job is done, then when you are doing this kind of sport, this can happen." The problem, the Tech3 Yamaha rider said, was that the front tire didn't want to turn. "It was sliding. Just sliding. You go into the corner and instead of turning, you go wide. Or if you want to turn you can crash. It was this kind of problem."
Dani Pedrosa had a similar issue, though his problem was with the rear of the bike. The Repsol Honda rider had a very good front tire and a lot of confidence with it, but the rear tire was simply not playing ball. "Unfortunately the rear was spinning a lot," the Spaniard said. "I couldn't really do better, I was losing a lot in corner 3 and the long left going up and some other corners in sector 4, everybody was getting by me, and it was difficult. Lucky that I had the front so I could go hard on the front to keep the pace, but, you know, unfortunately yesterday I had one not so good tire in the qualifying, and one today in the race." It definitely felt like it was the tire, Pedrosa added, and not the change in the track from previous days.
Finding the cause
The issue of consistency is one which Michelin is constantly working to address, Piero Taramasso, Two-Wheel Manager for Michelin Motorsport told us on Saturday night at Qatar, before the race. It was hard to pinpoint the exact cause of the inconsistency. There were many factors which could be responsible for changing the feel of the tires, and isolating a particular issue was difficult.
"It’s frustrating, because like I explained before, they complain sometimes, but behind that when we look at the data, they complain the soft from this afternoon was with less grip compared to the one in this morning," Taramasso told a small group of journalists. "So it’s completely different conditions. Or maybe they changed a setting in-between. Or maybe it’s not a grip problem. It’s just the warm up because they didn’t push enough in the hot lap. Or maybe because the tire was warmed in the tire blanket for only one hour, and the previous one was warmed for three hours. So there’s a lot, a lot of things they can change. But anyway, we listen to all the riders. We look at all the data. We look if they improve or not the lap times when we compare. Then of course we look if they did the test back to back without any setting change. So we look all these things. But it’s frustrating."
Could the complaints sometimes be down to the way the teams had handled the tires? "Yes, at times," Taramasso said, though for the sake of preserving relations between Michelin and the teams, he did not want to give a specific example. "I can't give you an example, but I can tell you maybe in between yesterday and today we had eight or nine complain, and when we analyze everything, only two complaints can be a problem."
The other complaints had nothing to do with Michelin, Taramasso said. "All the rest was just a complaint without any technical explanation, because from one session to another session they changed the setting, because they were in the traffic, because the lap time was different." Ironically, one rider complained despite having set a faster lap time. "There was one rider, they went quicker. So if it’s worse, how come you can go quicker? But again, it’s a very complicated subject."
Cradle to grave
The tires are followed very closely from production to the end of their life, Taramasso explained. "We follow each tire. It’s got a serial number, and we follow the tire from the building process to the transport, when it’s on the track, if it’s heated, if it’s refitted. We check the temperature, the storage temperature, everything. We try to understand where it comes from, when the problem is."
If there is a problem which is visible in the data, the tires are taken back to Michelin's base in Clermont Ferrand, in the heart of France, for further examination. The tires are dissected to examine the physical structure, and the chemical make up of the compound is verified. "That’s what we do," Taramasso said. "We cut. We do analysis, chemical analysis. We go back and look all the properties from the compound, if they were respected. We look at all the record about the transport temperature. We look how many times it was fitted or pre-heated. There’s a lot of work."
The tires are mollycoddled even during transport, shipped in climate-controlled conditions and monitored constantly. "We monitor all the temperature and our target is to have the tires always around 20-22 degrees," Taramasso said. "So even in the container there is climate control, heated. If you look in Europe, we transport the tire by truck. In the trucks you have air conditioning. The tire is not put in the metal rack. They are hanging in a hammock." The tires really are treated better than the technicians, Taramasso joked.
Once the tires are handed out to the teams, Michelin continue to monitor them, both in the tire racks and during use on track. Michelin has access to data from the tire pressure and temperature sensors fitted to the MotoGP machines. "We have access to the lifetime data," Taramasso said. "We can see the inner pressure and the temperature in real time."
They also monitor the tires while they are in the tire warmers, and the next step is to monitor how long each tire spends in tire warmers, and the number of times they have been heated. "Now we are working in a system that will be mandatory from next season. It’s a system which will record for each serial number of the tire how long it spends in the blanket. So then we will put a threshold. We say okay, after 85, 100, 150 hours of heating, the tire is no longer usable for the GP. The way we work now, we did some tests on the tire on the front and the rear, we check the compound and everything, after five or six days the tire. So it means two GPs. So after five or six days the tire is in the blanket, we withdraw it from stock."
Teams are advised to keep the heaters on all the time. "They put the switch on in the morning and then they switch off in the night. The next day, they switch on and off." The tires can go through five or six heat cycles before Michelin can no longer guarantee their performance. But the tire warmers don't take the tires up to maximum working temperature. "The blanket temperature is 90 degrees. The compound, the tires, they work at more than 120 degrees."
The tire warmers keep the tires at the bottom level of their working range, and warming them to that point did not affect performance, according to Michelin. "From our research results, this heating cycle doesn't affect the grip, but it might affect just the warm up. So maybe the tire takes maybe one lap more to warm up. That’s why I’m saying sometimes they complain the grip. It’s not the grip. It’s just that the warm up, the first or second lap, maybe you have to push a little bit more or do one lap more to get the tire in the right condition."
Taramasso did not believe that the teams were making a lot of mistakes in handling the tires, it was just that the riders ascribed particular sensations to the tires, rather than anything else. "Let’s say there are two or three riders that complain much more compared to other ones," Taramasso said.
"I don’t know if it’s the team who make them. I know it’s the riders who complain. The teams will look how they work, how they warm up. So for me, the teams they work well. It’s just the riders’ perception."
To head off any concerns about consistency during the race, Michelin are particularly careful about the way the race tires are handled, ensuring the riders have a selection of tires which haven't been previously warmed, and have been especially selected to be the best of each batch. "Like I said before, we keep track of all the life of the tire. We know the ones that are brand new. They’ve never been fitted or heated and they are very… We know also for the uniformity we have some tolerance. So we give them the best one. So each rider, they have one for each specification. They have one race tire."
Riders are told at the start of the weekend which tires should be the best for the race. "We tell them this is the best one, so please keep it for the race. If there is another tire that was warmed up or fitted or tested before, we say, 'This one was fitted last test, so use it in free practice 1. Use it as soon as possible.'" That doesn't necessarily mean that the tires deteriorate if they go through a heat cycle and is used after being warmed up a second or third time. "Just to be sure, we say, okay, just use it. Then they use it and they are okay."
Most of the complaints are about grip rather than anything else, Taramasso explained. "Most of the time it’s just grip. But we check also the uniformity to be sure that we have no vibration. Sometimes it happens, but it’s more about the grip."
Though Michelin monitor which are the best of the tires they supply, Taramasso explained the tire allocation system was still completely random, and handled by IRTA. Michelin handed IRTA the bar codes for the tires in separate groups or blocks, sorted by conformity to tire production specifications and by the number of times a tire has been warmed up. This ensures that each MotoGP rider has at least one tire from each specification (three front, three rear) which is of the highest possible quality. These tires are assigned at random by IRTA, with the bar codes selected by a computer program.
Taramasso explained the process to us as follows: "What we do before we send the list to IRTA, we make a special block for block number 1, block number 2, number 3. In each block we put one race tire, one race tire, one race tire. So everybody’s got the same amount. It’s not possible that you have two race and three already fitted. On the blocks, they have the same, then we give the blocks to IRTA. Then they assign the block with all the tires."
Given the continuing complaints from riders, there are still issues which need to be addressed. But as Piero Taramasso described it to us in Qatar, it is something they take very seriously indeed.
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