THE SIMULTANEOUS popularity of the ten-speed bicycle (bicycle sales now outnumber automobile sales in the United States.1) and the shoulder bag has introduced yet another hazard into modern life. The forward position of a cyclist on the modern, diamond-frame, ten-speed bicycle adds efficiency to pedaling efforts and cuts down resistance but at the same time gives insecure purchase for the strap of a shoulder bag (Fig 1). A small movement can cause the strap of the bag to slip from the shoulder, slide down the arm to the handlebar, and swing forward in a pendulum movement toward the front wheel (Fig 2). The rotating spokes of the front wheel catch the bag and wedge it solidly between the fork and the wheel. The front wheel stops precipitously, the bicycle turns end-up, and the rider is thrown over the handlebars, often with disastrous results (Fig 3). Report of Cases Case