The newly resurfaced infield section of the Indianapolis Motor Speedway has been heavily criticised, following Friday morning's first MotoGP practice session.
Turns 5 to 16 have been resurfaced for this year's event, to remove the bumps and inconsistent asphalt of previous seasons.
But world championship leader Casey Stoner claimed the new asphalt is so slippery it is actually worse than before.
"This morning was a little frustrating, the track conditions weren't very good, it was very slippery and it was difficult to find any grip," began Stoner, who was second fastest behind Ben Spies during the session.
"It was pointless trying to find a set-up with the track like this as it was worse than with the bumps in previous years.
"Hopefully by this afternoon there will be some more rubber laid down on the track and things will improve."
Repsol Honda team-mate and defending Indy winner Dani Pedrosa was even more scathing after finishing down in tenth place.
"The quality of the new asphalt is disappointing, not what a World Championship circuit deserves," claimed the Spaniard. "There is no grip and the level is very irregular.
"The worst thing is the entrance of the corner; you can control the acceleration with the throttle, but entering the corner there is no traction at all. Now, all we can do is to adapt as best we can to the track because I think it will not change very much.
"This morning we had the same problems from the first lap to the last. Therefore, we must be smart, find the setting that allows us to go faster and hopefully with more rubber on the track, maybe the conditions will improve a little, but now it's hard to say. We have to forget this and concentrate on doing our best under these conditions".
Third Repsol rider Andrea Dovizioso (seventh fastest) added that the new asphalt was like "riding in the wet".
Due to the slippery surface, Spies' best time of 1min 43.260sec was over three seconds slower than the lap record.
Spies' team-mate Jorge Lorenzo was another big name rider to struggle, the world champion finishing the 45-minute session in ninth place.
Second practice will be held this afternoon.
2011 is the final year of the existing Indianapolis MotoGP contract and, although the new Austin circuit will join the calendar in 2013, Indy is expected to agree a new deal for at least the next season.
California's Laguna Seca circuit has a contract with MotoGP until 2014.