Director of Moderation
I've wondered about that too because Pirellis are the same for the rear. The softer SC1 is typically recommended in really hot temps over the SC2 which doesn't really make much sense, but it really does work better. From a scientific point of view I don't really get it, but I'm also not a tire expert.MotoGP mutterings: Catalunya
THE MICHELIN MYSTERY SOLVED
How come the two hottest races of the year have been won by a rider using the softest front and rear tyres available?
At Mugello the track temperature was 51deg C and at Catalunya it was 45deg C. In such conditions, most riders would usually opt for the hardest compounds available, but MotoGP is far from usual these days.
“When it’s very hot you think you need to go harder and harder with the tyres, but it’s not like this anymore,” explained Aprilia’s Aleix Espargaró. “Last year [Johann] Zarco chose the soft rear on many super-hot race days, so the rest of us said, no way will he finish the race, but in fact he finished on the podium!
“I don’t have an explanation, but I think it’s something like this. When the track temperature increases, the grip improves and keeps improving, to a certain level. Then once the track gets hotter than around 40 degrees the grip starts to decrease, so when the track temperature is very high, you once again need the soft compound that you usually only use in cool conditions. The grip is less so you need softer tyres, because the tyre isn’t grippìng the track.”
In fact, most teams are finally getting the hang of the Michelin mystery. Despite the 45deg C track temperature on Sunday at Catalunya, all but four riders chose the soft rear slick, while more than half the grid chose the soft front slick. Alongside Lorenzo on the podium were Valentino Rossi, who also chose soft/soft, and Márquez, who chose hard/hard, because that’s what his riding technique and his machine demand. Could this be a problem for the world champion?
MotoGP is far from usual these days.
Michelin’s motorcycle racing manager Piero Taramasso revealed plenty of interesting information at Catalunya. Riders like Dani Pedrosa and Maverick Viñales are struggling partly because they don’t get enough heat into the tyres during the warm-up lap. Taramasso requests riders to ride the warm-up lap at no less than 95 per cent of full speed to bring the tyres towards peak temperature and grip for the start of the race.
Riders are now allowed to preheat their tyres to 100deg C, instead of the usual 90deg C, to help with this issue. They are also allowed to increase pressure by ten per cent before short, fast runs, to generate more heat and grip. But this wouldn’t be a good idea for a race tyre.
Taramasso also confirmed Crutchlow’s post-Mugello comments about his front tyre overheating while riding in a group, due to the heat coming from rival machines. “We can see it clearly on the data,” he said. “There is less cool air when you are riding in a group, so the tyre pressure increases and you lose grip.”
Riders tested a new-profile Michelin front during Monday’s tests at Catalunya. The tyre has a revised profile to increase edge grip, which should allow riders to brake deeper into corners. But the tyre cannot be raced until 2019. After last year’s midseason change of front-tyre construction flummoxed several riders, teams decided there should be no more midseason changes of tyre profile of construction.