In an aspect, a torsional vibration damper is provided, comprising a hub portion that mounts to a crankshaft, an outer ring that includes an inertial mass, a plurality of radial connectors that are elastically deformable and a plurality of spacers that extend circumferentially between the radial connectors and which are elastically deformable by the radial connectors during flexure thereof. The spacers are non-metallic and dissipate energy from deformation via conversion to heat. The plurality of radial connectors have a circumferential spring rate K1a in bending in a circumferential direction about the axis, and have an axial spring rate K1b in bending in an axial direction, wherein K1b is at least 10 times as large as K1a. The plurality of spacers have a circumferential spring rate Kra in the circumferential direction, and an axial spring rate Krb in bending in the axial direction, wherein Kra is less than 1% of K1a.