Inside a plain, brown building in Boulder, Colorado, is a shrine to an American icon: the Schwinn bicycles. Some mud-caked from daily use, some shiny museum pieces-dozens of bikes stand atop file cabinets and lean against cubicles. Amid the spokes and handlebars, a group of zealots is working to pull off the turnaround of the century in the bike business. Brimming with energy, they’re determined to resurrect the best known brand on two wheels. But as Schwinn celebrates its 100th anniversary, its management team faces a long uphill climb. Just two years ago, once-mighty Schwinn had a near-death experience in bankruptcy court. Now it’s trying to rise to the top of the crowded mountain bike market.