Friday's free practice for the Spanish Grand Prix saw several riders experiment with winglets, as Jorge Lorenzo displayed good pace.
Defending champion Lorenzo confirmed this week that he will leave Movistar Yamaha for Ducati at the end of the season, but showed his determination with his current employers remains by topping the timesheets in both sessions.
The Spaniard's time of 1'39.555 was one of just two sub 1.40 times set over the day, Marc Marquez's effort of 1'39.900 had been FP2's best for some time before Lorenzo bested him.
Much of the talk in the paddock was on the winglets being used by several riders, the aerodynamic fins attached in efforts to prevent wheelies.
Monster Yamaha Tech 3 rider Bradley Smith, who was 16th-quickest in FP2, urged caution over concerns about how the fins would affect bikes in other areas.
"When you're riding at 350 km/h and the bike starts shaking as the [brake] pads come apart, you don't have any front brake," explained Smith. "That's more dangerous than crashing into another rider.
"When you're at full [throttle], sixth gear and the brake pads come apart because the front has been wobbling around, that for me is a safety issue."