My guesses are on a rider from europe. Quite hard to guess tough because you can't see anything recognizable in the picture( it was way easier with yannick's picture). My guess would be on peter henke but i heard he signed with canyon.

 Aaron Gwin? I know that's a long shot but it would be hilarious.

 I don't think it's Gwin he is to expensive for Yt and he needs Racing Team!

 Cam Zink would be awesome for YT

 It is cam zink! That's sweet I hope it means yt is available in the U.S. now

 I'm going to guess.. Captain America

 looks like Greg Watts or Cam Zink to me. probably wrong.

 Cam Zink was in germany on Monday. Maybe for the picture?

 Aaron Gwin