Repsol Honda's Casey Stoner has admitted the amount of chatter and unsuitability of the new Bridgestone front tyre to his RC213V means he isn't able to get the best out of the V4-engined machine and it is hurting his title chances.

The reigning champion ended yesterday's Mugello MotoGP round in eighth after running off the rack at Correntaio. A tankslapper knocked the pads back into the calipers and he was left with no brakes going into the right-hander but the problems are more deepset than one error.

"I went into the corner and basically didn't have any brakes from the headshake before. The brake came back to my fingers and I thought I had enough power to stop but as I got to the edge of the track, I closed the front a couple of times so I eased off the brakes again and went into the gravel trap with too much pace so I wasn't able to stop quickly and turn to get back on the track," said Stoner, speaking to bikesportnews.com.

"It was game over, you know. It was already a tough weekend and a difficult race. I think we had the pace to be on the podium but unfortunately that was our goal going in and we blew it. I thought maybe we had the pace to go with Dani but in reality I think a third was going to be good.

"We just couldn't get the bike working and even in warm-up. We were really unhappy with the bike and not feeling comfortable at all. A disappointing end to a difficult weekend as I thought I might be able to salvage something from it.

"I chose the extra hard as it wasn't any worse than the hard. The laptimes were exactly the same as the other hard tyre we have and I couldn't see any negative in taking it. We'd heard that someone had even over-heated the hard tyre so we took that extra bit of comfort. We knew were weren't at a disadvantage choosing that tyre.

"Things haven't rolled our way this year sometimes and we have made our own mistakes. I think we have the chance to win a lot more races by the end of the year and we will see what happens. The biggest disappointment with our bikes is we haven't been able to fix any of our chatter problems and with this new tyre I can't find any feeling or confidence in the front. I can't attack the entry of the corner like I used to. I'm nervous on the brakes and I'm not getting the best out of the bike and tyres. I think that's the most disappointing thing."