Did Valentino Rossi learn how to knock Marc Márquez down from Fast Freddie Spencer? Nick likes to think so. (MotoGP/)As told to Cycle World from an anonymous source: Before YCRS, Nick Ienatsch instructed at the Freddie Spencer school. During the three-day schools the students and instructors would slide around on Honda XR100s. Fun was had by almost all. One day,…