An insert to provide a run-flat capability to pneumatic vehicle tires comprises a flexible, compressible, porous ring comprised of a plurality of successively-wound, circumferential layers of an elastomeric binder-coated filamentary material, the coated filaments having voids therebetween and being bonded to one another by the binder. The insert has desirable properties including lightweight, flexibility, and good load-distributing properties which make it a practical and useful component of any run-flat insert design for pneumatic tires. In preferred embodiments, the insert is spaced and supported from the tire by a member which minimizes the overall weight added to the tire. It is also further desirable to provide the insert with means to reduce its expansion radially upon rotation of the tire.