This girl's bike documents the popularity of cycling as a mode of transportation, a leisure activity, and a sporting pastime. The bicycle is a childhood artifact familiar to most 20th-century Americans of all classes. In the last years of the 20th century, the popularity of the bicycle encouraged manufacturers to produce bikes of specialized use. Racing bikes became stripped-down, light-weight speedsters. Urban bikes were built for the asphalt surfaces of the city. Mountain bikes featured sturdy construction and reinforced shocks to absorb the bumps of rough terrain. Bikes became available in all sizes--the teeniest for four- and five-year olds; the largest ones for serious bikers of large stature.