Marlboro Ducati's Valentino Rossi and team-mate Nicky Hayden will ride experimental versions of the Desmosedici GP12 on day one of the Valencia MotoGP test tomorrow and, according to boss Filippo Preziosi, it will be nothing like the bike they will race at Qatar next year.

Both the riders will run the full aluminium perimeter frame designed by FTR and Preziosi also hinted they may change the angle of the engine's V in order to be able to put more weight over the front wheel to load the Bridgestone tyres more.

"The bike tomorrow with the perimeter frame will not be the bike for the first race. It is an experimental bike, really a prototype bike to give to our designers the targets to design the bike for the future. We don’t expect that at the test we will have a step in performance because the bike is more or less the same as the current bike but with a different technology We would like to realise a bike with a different type of chassis with the same geometry and weight distribution," said Preziosi, speaking to bikesportnews.com.

"We believe the engine based chassis is a good idea in general but in the MotoGP championship there are some constraints. The first is the tyre, which are very good but they require special chassis in terms of stiffness. The other point is the number of engines are limited so when you have an engine based in the chassis, if you want to change some dimensions or weight distribution you have to redesign the tooling to do new cast parts, machine it then put in the new engine. This is a big economic effort and quite impossible to do with six engines. For these reasons we have to change this."