Mankind has invested more than four million years of evolution in the attempt to avoid physical exertion. Now a group of backward-thinking atavists mounted on foot-powered pairs of Hula-Hoops would have us pumping our legs, gritting our teeth, and searing our lungs as though we were being chased across the Pleistocene savanna by saber-toothed tigers. Think of the hopes, the dreams, the effort, the brilliance, the pure force of will that, over the eons, has gone into the creation of the Cadillac Coupe de Ville. Bicycle riders would have us throw all this on the ash heap of history.