Got any training wheels?

Putting political and ideological differences aside for just a moment: What is with this guy and two-wheeled vehicles?!?!

President Bush collided with a local police officer and fell during a bike ride on the grounds of the Gleneagles golf resort while attending a meeting of world leaders Wednesday.

This little accident, combined with this one and this one, seems to imply the guy needs to stick with cars from now on.