A resistance generating device includes a friction wheel adapted to frictionally engage a bicycle wheel of a training bicycle to be rotated therewith, a first magnetically attractive member, and a second magnetically attractive member which is rotated with the friction wheel, and which is disposed to be spaced apart from the first magnetically attractive member. The SS is in a power-saving state. The endless track extends about the first track-engaging wheel and the second track-engaging wheel, and the track has a tension.