For controlling 1.sup.st and 2.sup.nd torsion characteristics in a disk drive suspension, a disk drive suspension is provided having a beam portion with edge rails extending along its edge regions, the edge rails are locally varied substantially identically between lesser and greater heights along their lengths, the beam portion having a central region increasingly extending above or below the plane of excitation in inverse response to the edge rails increasingly or decreasingly extending above the plane of excitation. The inverse relation of the beam portion central region and the rail heights relative to the plane of excitation tends to offset in at least part changes in the balance of the suspension upper and lower inertia components from changes in the geometry of said suspension.