Abstract: A system for converting a bicycle into a bicycle exerciser comprises a bicycle exerciser support having a base stably resting on the ground, the base having a pair of divergent integrally attached side legs. A pair of upwardly projecting support arms are integrally attached to the base side legs, and merge at their upper ends into a female coupling member. A complementary male coupling member is attached by means of a bracket to the seat tube of a conventional bicycle, under the seat thereof. Thus, the bicycle can be installed on the support by simply vertically resting the male coupling member onto the female load-bearing coupling member, for idling the rear tire which then becomes spaced over ground. A drag device comprising a dragging endless belt engages the rear tire, for selectively dragging the tire and offering resistance to the now stationary bicycle driver when pedalling.