The championship leader had to serve a long penalty in Sunday’s 20-lap race at Silverstone as punishment for his collision with title rival Aleix Espargaro in the Dutch GP in June.
Quartararo ran second in the opening three laps before serving his penalty on the fourth tour.
Though he only lost around 1.6s, he dropped from second to fifth and plummeted to eighth by the chequered flag as his medium rear tyre overheated as he ran in a pack.
Asked if he was disappointed with a race in which his championship lead over Espargaro – who was just behind in ninth – grew by just one point to 22, Quartararo said: “Yes. Disappointed because I thought the long lap would have penalised me much more, and finally it was not so bad.
“But just the rear tyre was so bad and behind riders we cannot ride our bike.
“It’s just a nightmare. If it’s just one bike, it’s ok, but if there is more than one bike the rear tyre was so hot and it loses performances, then it goes down and then you are riding in a totally different way to the others.
“And for us to then overtake [on this bike] is a nightmare.”
Quartararo says the tyre he should have used in the race was the hard rear – which is what winner Francesco Bagnaia on the Ducati ran – but Yamaha made a mistake in not testing it in practice beforehand.
And without the penalty, the Frenchman believes he could have stayed at the front as only running behind one bike wouldn’t have caused him so many issues with his tyre overheating.
“I think yes because our problem was not the distance [we lost taking the penalty] because at the end we lost 1.5s [in the penalty], but it was not bad,” he replied when asked if he could have stayed out front without the penalty.
“But just if it was only one bike [ahead of me] and I lost 1.5s, then it was ok.
“But just when we are behind some riders, my rear tyre got super-hot and we don’t understand why… of course we understand why, because with the other machines [in front of us] and the heat [from them] the rear tyre goes way too hot and we lose performance and it drops.
“With the hard it would have been better, but it’s always easy to talk after the race.
“We didn’t try the hard rear tyre, so we made the mistake of not trying the hard rear tyre.
“So, we made a mistake but that’s the problem. We didn’t try the hard tyre and this condition was super important to use this tyre.”
