Abstract: An attachment which converts a stationary exercise bicycle into an electronic exercise machine. A base tube of the bicycle frame can be strapped to a floor plate to which an alternator is hinged. The alternator can be raised about the hinge axis so that a drive wheel on the alternator drive shaft is applied to the driven bicycle wheel. The alternator is maintained in its operating position by a rope and cooperating springs. By electrically controlling the field coil of the alternator, the load applied to the bicycle wheel can be varied. Electronic features include programmed exercise routines and visual displays of time, load, speed and pulse rate.