At the conclusion of the second Sepang MotoGP test session, Honda was once again atop the timesheets with both of their factory riders. That said, the manufacturer from Tokyo has seen their advantage slowly erode, especially with regard to their main rivals Yamaha, to the extent that HRC vice president Shuhei Nakamoto feels they no longer have the best bike on the grid.
"The M1 is very fast and represents a significant obstacle for us - the manager said - we aren't at the same level. The Honda is very powerful, but the Yamaha has great handling. As a package, they have the best bike at the moment."
Perhaps this is because of the chattering that Casey Stoner has lamented since the first Sepang test: "We have some other small issues to resolve, but chattering remains our main problem. It isn't so much a problem on the brakes as it is mid-corner. The frequency of the vibration changes significantly, depending on the shape and speed of the corner."
Since Honda didn't really have this problem last year, the culprit could be either the increase in minimum weight (from 153 to 157 Kg), the new Bridgestone tires, or some combination of both. "The rules change to raise the minimum weight has penalized us, also because it cost us more money in development, but I think it's mostly the tires that are causing the chatter. Bridgestone is working hard, and they have provided some new compounds at the test, but unfortunately the tire that gives us less chattering is the one with inferior performance."
Also causing concern was the race simulation carried out by Jorge Lorenzo, where the Spaniard lapped consistently under the 2'02 barrier. "Unfortunately we couldn't do any long runs because we lost the entire second day of testing, and we had many things left to try. We weren't sure exactly what happened with the engine, and the safety of our riders is the top priority. But on day 3 we didn't have to change anything, not even in terms of power output. We didn't change the mapping or any of the engine control software."
source: GP One