The rider of a horse in a race is called a Jockey.

derrick suber

I don't believe that Phar Lap raced in the USA.

400 lbs for total weight.

The cast of Elements - 2010 includes: Wess Agee as Himself - Rider Coy Cooper as Himself - Rider Logan Darian as Himself - Rider Jeff Fehr as Himself - Rider Jimmy Fitzpatrick as Himself - Rider Heath Frisky as Himself - Rider Derek Garland as Himself - Rider Steve Haughelstine as Himself - Rider Broc Hepler as Himself - Rider Justin Homan as Himself - Rider Devin Karr as Himself - Rider Jim McNiel as Himself - Rider Todd Potter as Himself - Rider Ronnie Renner as Himself - Rider Miles Richmond as Himself - Rider Keith Sayers as Himself - Rider Greg Shaft as Himself - Rider Reagan Sieg as Himself - Rider