Provided herein is an apparatus, including a fluid dynamic bearing, wherein the fluid dynamic bearing includes a set of pressure-generating grooves, and wherein the set of pressure-generating grooves includes a plurality of chevron-shaped grooves, each chevron-shaped groove including at least two selected from a non-uniform depth, non-uniform angle, a non-uniform width, or a non-uniform length, selected to provide a predetermined spindle-motor stiffness to the journal bearing during steady-state operation and during a shock event.