On Saturday, Bradley Wiggins will roll down the ramp and begin the short, 4 mile time trial Prologue around the Belgian city of Liège that will signal the start of the 2012 edition of the Tour de France. Wiggins, in the form of his life after back to back victories this Spring, will be aiming to ensure that he starts the Tour de France in the manner he hopes he will end it - wearing the coveted y…