Word Study
Safety bicycle
CIDE DICTIONARY
Safety bicycle,
A bicycle with equal or nearly equal wheels, usually about 28 inches diameter, driven by pedals connected to the rear (driving) wheel by a multiplying gear. Since the 1930's this has been the most common type of bicycle, now simply called bicycle . The older high-wheelers are often referred to as bone-rattlers . [Webster 1913 Suppl.]
For further exploring for "Safety bicycle" in Webster Dictionary Online