As they say it really is weird since Michelin has always been known for the quality of their tires. I do love the SOP response from Crutchlow in there
Sounds like there are some process or things going on that wont show on normal QC. If it was batch to batch issues its usually easier to find out what happened that was different between the 2 batches. If they cant make the same tire from the same batch of rubber...then they have some other issues related to batch processes (mixing energy, temperature, etc) and that should really scare them. Sounds like they arent doing something to the rubber during mixing, either not enough or too much. If those numbers they quoted in the article about wheel spin vs throttle position etc are true...man they got some real issues. Glad Im not in Michelin QC...
apparently Michelin's tire warmer procedure is "turn them on the morning and turn them off at the end of the day". so the tires bake all day. teams often mount all their tires at once and don't use them all. so its possible for a tire to be baked all weekend and then mounted at another round. they keep track of all this. teams are warned not to race on older tires and a tire will be tossed if it really gets too many heat cycles on it. I think Michelin is looking at revising all this a bit. but Im a little surprised it was even a problem to begin with.
Other than Nakano (which was before the spec tire rules, if I remember right) did Bridgestone ever have another failure? I don't remember any, but I do remember some in the paddock feeling they were head and shoulders above the Michelins (at least, while Stoner was on them).
I wouldn’t think they would cary over any tires from one event to the next outside of what they use to transport the bikes. ?
I can't say you were totally wrong (obviously the article says what you say it does), but they say they are only brought up to 120 during these heat cycles (i assume celsius).. they aren't brought up to full temp till they are ready to be mounted on the bike. Not exactly "baking all day", but it is at least one continuous heating cycle, however it's nearly a 60 degree F difference in the warmer temp it's kept at, vs the temp it gets cranked up to for going on track. Could this still contribute to issues? i don't think you or I could do anything but speculate. the guys designing and formulating the tires don't seem to think so. Are there some issues with consistency? Some riders and teams seem to think so. The article also went on to say any tires used for the actual races, are never previously warmed. So there's some consistency there at least (if that's actually what happens). -------------------------------------------- Heating cycles 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."
of course we are only speculating. thats the fun part! Michelin saying "90C all day does nothing to performance" is at odds with giving them 1 tire each that hasn't been warmed before. that bit is a little fishy. of course, IF (a big if) teams only use those tires for the race, then the largest consistency issues should def not be caused by extra warming. none of the teams seem to be immune to these issues. I wonder if they are def racing on the right tire or if they are following the warmer procedure perfectly. hell, I wonder if they bother warming their race tires on Fri and Sat.
Check the cooking thread for the solution. Sous vide. Can't believe the french havn't thought of it already... Keep the vacuum sealed tires in a big heated pool. When needed, take them out and reverse sear them before use. Make the teams fish for them like carnival ducks, and randomly throw in a hard to catch extra soft before qualifying. There's been a couple complainers about "bad tires" last year and now this year. They all have the data, and experience, so I don't think they're blaming the tires for them having an off day. Hopefully they sort out the cause, and find a solution because races being decided by the quality control of a "spec" component is pretty shitty.
who's the fastest rider for a given weekend to complain about a tire from a race? someone that actually should have competed for the win, not just challenged for 5th-10th. Dani at Qatar comes to mind, but he didnt really have it to challenge MM or Dovi no matter what. not Zarco at Qatar, he never had it. I don't rem MM or Dovi complaining about a race tire. Rossi and Mav had tire issues all last year that weren't Michelin's issue. what race am I forgetting about?
“We’ve got a massive issue with the consistency of the Pirelli tyre,” a frustrated Haslam told MCN. “I had the issue yesterday but wasn’t 100% sure and thought it might have been an isolated issue, but I now think it’s something to do with the 2018-produced tyre. They seem to be a second a lap slower and last half the distance compared to 2017 tyres…" source: https://www.motorcyclenews.com/spor...sb-haslam-hits-out-after-donington-tyre-woes/
