Valentino Rossi admitted set-up tweaks ended up compromising the balance of his Yamaha YZR-M1 on the second day of MotoGP winter testing at Sepang.
The Italian finished more than seven tenths of a second down on teammate Jorge Lorenzo, his largest deficit yet to the 2012 MotoGP champion. Rossi said an effort to improve rear traction on race simulations had, while successful in itself, compromised the balance of his bike.
"We continued to work to increase the rear grip and traction, especially when the tire has a lot of laps," Rossi explained." We improved something but we are not 100 percent happy, because to improve the rear we lose a bit of the balance, which was [previously] very good."
Despite the setback, and an early electrical glitch, Rossi said he was still pleased with his progress heading into the final day in Malaysia.
"The feeling is quite good, I'm happy, especially as today was a long day. [We] did more than 60 laps because we worked a lot. Tomorrow the target is to try and improve the traction without losing the balance and the rear of the bike, which is very good [with the original setup]."