An analysis of antilock brake system dynamics, based on nonlinear control theory, was performed. Results were used to define initial performance and design requirements for a prototype fluidic motorcycle antilock system. The analysis emphasized the frequency response of system components and effects on stopping performance and stability. Results showed wheel angular acceleration provides a feasible single loop feedback for antilock control;​ wheel angular jerk is probably not a desirable primary feedback variable;​ nominal design requirements for modulator and controller exist that represent a compromise among high and low μ performance, stability, roughness, and signal-to- noise ratio;​ net time delay between modulator and brake caliper is a key design parameter and should be investigated more thoroughly.