Barcelona has typically been a strong venue for Yamaha, though the circuit's low-grip nature has worked against the M1 lately with its traction issues.
Despite this, at one point in second practice it looked like both factory Yamaha riders could secure a direct place in Q2 for Saturday’s qualifying.
However only Alex Rins was able to break into the top 10 come the conclusion of the second practice in ninth.
Quartararo will face Q1 after being left with no time for a proper time attack at the end of the session, “a mess” he has blamed on a chain change by his Yamaha team taking too long.
“A bit better,” Quartararo, who also suffered a crash early in second practice, said of his feeling on the Yamaha at Barcelona on Friday.
“The aero is doing what we expected. It’s a shame it was a mess for the time attack.
“We took so much time to change one thing on the bike and I could do only one lap in the second run with yellow flags, so I could not make the lap.
“If you check the pace, the pace was pretty good. Missing the Q2 for this reason is not the best, but I think overall the base was a lot better than before.
“[It] was the chain. The length of the chain, because we tried a longer swingarm.
“The other bike was crashed, but the problem was we stopped way too late because if it was good, it was perfect.
“We stop, change the tyre and go. But it was not great. So, we had to change and we lost 10 minutes there. Unfortunately, it was the worst 10 minutes of the weekend.”
The 2021 world champion also noted that Barcelona is one of several tracks this year where he's unable to gain much on a fresh soft tyre in time attack trim, but doesn't know why this is the case.
“There are a few tracks where I am struggling a lot and we have no idea why,” he said.
“I make 1m39.6s on the pace. Why can I not do [more] than 1m39.3s on the time attack?
“This is something I don’t understand, because on the pace we were super fast for us; compared to the others it’s different.
“Our pace was really good, but when we put on new tyres we cannot understand. Because Alex, if you check his pace over one lap, there’s a big difference.
“But for us no. This is something that I try to understand and the team also wants to try to understand.”
New Yamaha aero worth 0.2s per lap, but Barcelona not showing it
A major bike set-up shift for Rins allowed him to make a step forward in form on Friday at Barcelona.
Yamaha also debuted for both riders its newly-homologated aero package that was first tested at Jerez after the Spanish GP, and then refined at a private test at Mugello last week.
Quartararo noted that the new aero was an improvement under braking, while Rins noticed a slight benefit in cornering.
However, Barcelona’s low grip means the benefits of the new aero package are being lessened – according to Rins – and its potential at the Mugello test was at least 0.2s per lap.
“In this track, I don’t think it helps a lot,” Rins explained.
“With the lack of grip, the problem is more on the rear than more on the front or the corner speed.
“For sure it helps. With this fairing, I felt I could do a bit more corner speed, the bike held the line.
“But we had more problems on the rear. It was much better in Mugello, maybe 0.2s faster.
“So, in the end as a rider you want more than 0.2s, but 0.2s per lap is seconds [over a race].”
