It is important for the physician to understand bicycle safety equipment in order to prevent and treat bicycle-related injuries effectively. The physician should understand (1) the basic design and function of bicycles, (2) the relationship of improper bicycle fit to injuries, (3) the potential of the various forms of serious riding and racing for injury, and (4) bicycle safety equipment and the standards involved in its fit, manufacture, and care. A decision to use bicycle safety equipment is a decision to control the risk of injury. Physicians should accept a share of the responsibility for decreasing bicycling-related injuries, because they are viewed by the public as credible sources of information regarding the prevention of accidents and injuries.