By Lynne Huntting

Anthony West finished the first ever MotoGP session at the Indianapolis Motor Speedway on top of the timesheets.

On Friday morning at Indianapolis Motor Speedway, before the first 90-minute practice session for the Red Bull Indianapolis GP, the weather was cool and damp. The rain then came down lightly and sporadically during the part of the first MotoGP practice session, and parts of the track were drying faster than others.

Kawasaki Racing Team rider West, renowned for his wet weather ability, was fastest for much of the session which concluded with the Australian 0.117secs ahead of MotoGP rookie Alex de Angelis, of San Carlo Honda Gresini.

Dani Pedrosa of Repsol Honda, making his Bridgestone race debut this weekend, was the slowest of the 19 riders on track during the extended session, which saw no significant incidents other than a late fall for reigning world champion Casey Stoner.

Stoner still claimed third for Ducati, while world championship leader Valentino Rossi eleventh for Fiat Yamaha.

Leading the American challenge was Kawasaki's John Hopkins (fifth), followed by Repsol Honda's Nicky Hayden (eighth), Rizla Suzuki's Ben Spies (ninth) and Tech 3 Yamaha's Colin Edwards (15th).

The two MotoGP tyre suppliers, Bridgestone and Michelin, have concerns about which tyres to use this weekend.

The main concern is the track surface and how much grip it will have in the ever changing weather. The tyre engineers spoke of the several different levels of grip around the track. One cited Turn Three as having three changes within the one corner, and cracks in the pavement which could be significant for the 125 riders. The task is how to best balance the grip and the tyre to make the best compromise. MotoGP riders hoped the 125 riders, who went out first, used their soft tyres to lay down rubber.

The track surface varies from corner to corner and indeed within a couple of the corners, with stretches of asphalt being laid at different times.

Starting with the front straight, the track is the existing oval surface. Turns One through Four, a new road course section for this race, the surface has new pavement. Turns Four to Six is the existing oval track. Turns Six to Nine is another new road course section with all new pavement. Going onto the back straight from Turn Nine to Sixteen, the surface is existing pavement. In Turn Sixteen there is new pavement, which has been tweaked a couple of times.

An official MotoGP tyre test was held at IMS the first two days in July, but conditions were different. Those riders, with the exception of Spies, who is not a regular in the series, were test riders.

Spies made his MotoGP debut replacing the injured Loris Capirossi at Donington Park and ran the other US MotoGP round at Mazda Raceway Laguna Seca as a wild-card - a role he again plays this race with the same Rizla Suzuki team.

This means all the riders this weekend will be on a new circuit with weather conditions not yet experienced this year, and in the case of Pedrosa, a new motorcycle.

Second free practice for the MotoGP class will take place this afternoon.