“On day one we worked on the setting up and it influenced day two as we improved our times in spite of the considerable chattering.
“Today we had planned to try another chassis but the rain stood in the way of our plans,” he added.
“I am glad because the team and the technicians can get along pretty well and it is crucial to complete a good season.
“Now we are going to have a little rest and celebrate Christmas and we'll resume work so we can be fully prepared for the season to come up.”
Both riders set their best times on the second day of the test at Jerez, where they shared the circuit with Ducati and several World Superbike teams before the winter ban came into effect on Saturday.
Barbera managed a lap in 1m 42.507s with Aoyama slightly quicker in a time of 1m 41.975s, compared to factory Ducati rider Nicky Hayden's fastest lap on day two in 1m 40.090s.