How do you analyze and optimize secondary ride (high-frequency harshness)?

Secondary ride analysis addresses frequencies above 5 Hz where occupants feel harshness rather than motion. The approach involves: Identifying transmission paths from road input through tires, suspension, body structure, and trim to occupants, measuring and modeling each path's transfer function, analyzing tire envelopment and cavity resonance, optimizing suspension bushing frequency characteristics, tuning damper high-speed valving, and ensuring body structure modes are outside critical frequency ranges. Tools include modal analysis, transfer path analysis (TPA), and acoustic measurements. Solutions often require collaboration between dynamics and NVH teams for optimal compromise.