It’s the new, 2010 YZ 450 F – made exclusively for motocross and supercross racing.
We’ll have more photos and info soon. In the meantime, here’s a couple of nice photos of the bike that James Stewart will be riding in Supercross 2010, and a preview video:
Close up 2010 Yamaha YZ 450 motor
The 2010 Yamaha YZ 450 F