Abstract: This invention is an apparatus for quantitatively measuring the fit of an individual to one or more bicycles or other such human-powered conveyances. The apparatus comprises at least a three-dimensional marker tracking system, a software-based data analysis and presentation computer system, and (if necessary) a means of supporting a bicycle in a stationary location such that the individual being fit can pedal their bicycle in a normal yet stationary manner. In advanced embodiments, the system includes a means of simulating a bicycle, and perhaps even a means of altering the position of the bicycle components to perform a bicycle fit in a fully automated way.