For two decades, Davis Phinney was one of America's most successful cyclists. He won two stages at the Tour de France and an Olympic Bronze medal. But after years of feeling not quite right, he was diagnosed with early-onset Parkinson's. The body that had had so long been his ally had slowly morphed into something else: a prison.    The Happiness of Pursuit is the story of how Davis sought to overcome his Parkinson's by reaching back to what had made him so successful on the bike and adjusting his perspective on what counted as a win. The news of his diagnosis began a dark period for this vibrant athlete, but there was also light.  His son, Taylor, discovered bike racing, and as his career was taking off,  Davis wondered if he would spend the rest of his days quaking ineffectually on the sidelines of life. Determined to beat the Body Snatcher, Davis underwent a procedure called Deep Brain Stimulation. While not cured, his symptoms abated enough for him to see Taylor compete in the Beijing Olympics. On his own terms, Davis Phinney had won another stage.  But the real truth was that the joy was in the pursuit.   With humor and grace, Phinney weaves the narrative of his battle with Parkinson's with incredible tales from his cycling career and from his son's emerging career. The Happiness of Pursuit is a remarkable story of fathers and sons and bikes, of courage and optimism, of victories large and small.