This study is dedicated to the design of a ball-type balancer system installed on the high-speed disk drive in order to reduce radial vibrations of rotors caused by eccentricities of disk's center of gravity and circular runway of the ball balancer. The ball balancer is a promising candidate due to its low cost and capability to completely eliminate radial vibrations under the conditions that runway eccentricity, damping and friction are not present. A mathematical model was established first for the analysis of the dynamics of a rotor-balancer system. The influence of concerned parameters, e.g., runway eccentricity and rolling resistance, on residual vibrations was then explored through solving the equations for steady state solutions. The results were used to evaluate the performance of balancers in terms of vibration reduction. The design guidelines for minimizing the vibrations by controlling the aforementioned concerned parameters were provided based on the parametric analysis conducted. Finally, experimental study was orchestrated and performed to verify the validity of the mathematical model and demonstrate balancer capability for reduction of radial vibrations.