The Italian set a new lap record on Saturday in France to claim his second-successive pole position and Ducati’s first at Le Mans.
Bagnaia led Ducati teammate Jack Miller by 0.069 seconds in the end, but was not confident of being able to fight for pole during the preceding 30-minute FP4 session because he was “struggling a lot” to stop the bike.
But he revealed after qualifying that he took “a bet” on set-up with his crew chief and Ohlins suspension technician which ultimately proved successful.
“First of all, this morning I was happy, but when it’s cold it’s easier to go fast at this track,” Bagnaia said.
“This afternoon in FP4 I was not sure about the pole position because I was struggling a lot.
“My biggest problem was to stop the bike, that was the biggest problem.
“Then in qualifying we made a bet with my crew chief and my Ohlins technician, because I was not feeling great.
“And then after this little modification I started to feel great again as if it was morning.
“So, the grip was better, I was able to stop the bike better.
“And finally, the feeling was great. So, I’m happy for the pole position, I’m more happy about finding something that helped me a lot.
“I think we are ready for the race tomorrow.”
Bagnaia is expecting once again to go head-to-head with reigning world champion Fabio Quartararo in Sunday’s race just as he did at Jerez two weeks ago, but is wary of rain affecting the grand prix.
“For sure Fabio is the man to beat,” Bagnaia added.
“But I think that after this modification I did in qualifying, I’m closer now.
“But it’s difficult to say now. The forecast says it will rain tomorrow. I hope it won’t be like this.
“If I start well and if it’s dry, I will try to push from the start and try to manage a gap.
“But if it’s wet it will be another story. You can’t push like you want at the start, you have to control the situation more. So, it can be totally different.”