Long before Tiger Woods, or even boxer Jack Johnson, there was Marshall ”Major” Taylor. The African-American cyclist dominated the exclusive sport a century ago, when racers earned eight times more than baseball’s top stars. Todd Balf revels in the bicycle’s bone-shaking evolution and the top-gun fraternity of daredevils who literally risked life and limb to race. But Major remains a cipher, perhaps due to his self-imposed cocoon against a crudely prejudicial press that called him a ”rubbery little Indiana coon.” Balf masters the history in Major, but like post?Lance Armstrong cycling, a story without a compelling hero is just spinning its wheels. B?