Stefan Bradl worked his way through a long list of changes during 72 laps around the Aragon circuit, during Wednesday's MotoGP test.
The German rookie initially got his RC213V set-up for the track, which will host round 14 of this year's championship, then continued working on suspension and chassis stiffness.
The Honda LCR rider finished the day in ninth place, two-seconds from Yamaha's Jorge Lorenzo.
"Well, we have done a lot of work today: at the end I lapped the circuit 72 times and I feel a bit tired now," said Bradl.
"We found some good improvements ahead next races but when you work on different adjustments you lose track time... that's why my lap time is not excellent.
“We have changed suspensions, swing-arm, front fork and other things. We were expecting a different feeling with the tyres on this asphalt but with today's hot temperature they worked differently.
"I am pretty sure it was a hard-working day for everybody, but I am a rookie and it's essential for me to ride this bike as much as possible."
Bradl will be back in action at Silverstone next weekend, the scene of his final Moto2 win during his title-winning 2011 season.