On a balmy Wednesday morning, bike racks outside the Thompson Center are clogged with cycles. The drum-shaped building is nicknamed the &ldquo;Tom Tom&rdquo; by messengers who chill in the plaza while waiting for work. But today a cleaner-cut crowd has pedaled here in suits and skirts for the ThinkBike symposium, &ldquo;a Dutch boost to Chicago&rsquo;s [...]