Ben Spies has revealed that he made his decision to leave Yamaha some time ago.
The American stunned the MotoGP paddock by announcing on Tuesday that he was quitting the factory Yamaha squad after two years.
The move was revealed in unusual fashion, with Spies hinting on his Twitter feed that "big things are happening" and "next year will be a bit different", before emailing the Superbike Planet website to reveal he was leaving Yamaha.
"I've known for quite a bit what my personal decision was, and just knew that now was the right time to [announce] it, with all the contracts happening with other riders, to be at the ballgame with that. That's basically it," said Spies.
The former Superbike world champion declined to expand on his reasons for leaving Yamaha, or to comment on his 2013 destination.
"There's a litany of reasons behind it, and just to get back to being stress-free and doing what I want to do, and finishing the season strongly," Spies said.
"That's all that's going to be said about it at this point until I'm ready to talk about the future."