In a taut band suspension instrument in which each taut band extends between two convex support surfaces and the end portions of the taut band are secured to the respective supports by fused metal connections at points spaced radially from the axis defined by the band, the support surface at the end of the band farther from the rotor is provided with a shallow groove, the bottom of the groove being continuous and uninterrupted and having a width at least twice the width of the taut band, the support surface at the other end of the band being smooth and unbroken for the full width thereof. The combination of the two support surfaces allows the taut band to shift laterally when the instrument is under shock, yet assures that the outer end of the taut band will be properly oriented when installed and thereafter.