A stationary exercise machine includes a system for electronically
controlling a pedal resistance so as to simulate the riding of a
road-going bicycle. The exercise machine includes a control system that
monitors pedal velocity and that controls the resistive load generated by
an electronically-controlled resistance mechanism. In one example, an
electromagnetic device may vary a resistive load placed on a flywheel,
which, in turn, varies the pedal resistance experienced by a user. When
the user increases the pedal velocity, the resistance mechanism increases
the resistive load. When the user decreases the pedal velocity, the
resistance mechanism decreases the resistive load. In another example,
the resistance mechanism varies the resistive load based on a gear
selection by the user. The control system may also take into account
other factors, such as the grade of the simulated ride, simulated wind
resistance, or other frictional forces when calculating the resistive
load.