Max Biaggi's World Superbike Championship lead has been reduced for the first time since Assen after chatter problems prevented him from making it onto the podium at Brno.

The Italian came to the Czech Republic with a sizeable 48 point lead over Marco Melandri having steadily built his advantage since assuming the championship lead at the end of round three, but left himself with a task to maintain this run when he qualified down in 14th position.

Hampered by chatter woes in both races, though Biaggi made progress to finish in sixth and fourth, Marco Melandri's double win means the Aprilia rider's lead has been slashed to 21 points with five rounds remaining.

Disappointed to have problems with the RSV4 whilst utilising a setting that was successful at Motorland Aragon, Biaggi is hoping he can return to form at Silverstone.

"Unfortunately we couldn't do any better than we did today," he said. "We had some big problems with chattering which compromised every move I made. In race two I tried not to lose touch with the front pack, but I just couldn't maintain their pace.

"I was already at the limit as if it were the last lap. We still haven't figured out what the problem is, since both the bike and the set-up are very similar to what we were using at Aragon. I just hope that we don't have the same problem in the rounds to come."