Newly-crowned World Superbike Champion Mx Biaggi is on the verge of signing a new deal to remain with Aprilia for 2013, saying he only has some non-fiscal details to iron out.

The self-styled Roman Emperor set the second quickest time at this week's three-say Motorland Aragon test but says he has a lot of work to do to adapt the RSV4's electronics to the new 17in tyres.

"If I'm already putting on a helmet again, just a few days after winning the championship, it's pretty clear what I want to do. We still have some issues to work out, not about money, but about other details," said Biaggi to the stout chaps at GPone.com.

"Moving away from the 16.5in tyre means completely overhauling the electronic strategies used up until this point. The diameter and profile of the tire are different, so we need to completely change the settings of the electronic controls. It's a long process, and it must be undertaken by the electronics engineers at the factory."