Jorge Lorenzo, YamahaMotoGP champion Jorge Lorenzo believes Yamaha and Honda's rivals will have cause to regret not joining them for their private Circuit of The Americas test, given how hard it is to master the track.

The factory Hondas and Yamahas, plus LCR Honda rider Stefan Bradl, are testing at MotoGP's new American venue this week. After Tuesday's opening day of running, Lorenzo said he liked the COTA layout but was very relieved to have extra time to learn it.

"I think it's very important to come here and learn the track," he said. "I haven't learned  100 percent of it, I need more laps to learn my lines, but for the moment it's a very beautiful track which is very complete with every kind of corner.

"In the beginning it was difficult to understand the lines but I have improved by three seconds from the first lap. That means it's a hard track to learn and a difficult track to go to the maximum on.

"I think it helps more than some other places to have this extra time. I think three or four practices before the race will not be enough to understand it so some of the riders who didn't come here will have a little disadvantage."

Honda's Dani Pedrosa reckons Austin is unlike anything else on the MotoGP calendar.

"It is a new circuit, and a very different one at that," he said. "The track has a lot of tight corners -- above all Turn 1 -- but there are also flowing chicanes and some long straights. The pace and direction changes from section to section, which is a little strange at first."

Dani Pedrosa, HondaLorenzo's teammate Valentino Rossi is also a fan of the venue, although he believes some elements are more suitable for Formula 1.

"It's very flowing with a lot of fast corners and a lot of change of direction; it is fun on the bike!" said Rossi. "There are three hairpins that are very tight; this is better for Formula 1 overtaking, but for us they are a bit slow."