Michelin’s Puncture-Proof Tire Prototype Could Make Flats a Thing of the Past
6th June 2019
Though the tire has conventional treads, the middle layer is made of composite rubber and resin-embedded fiberglass spokes. The spokes provide support for the treads and remove the need for air.
I have seen a number of proposals for this sort of technology — basically, the tire rim is supported by a series of springs — but this appears to be close to production. The key will be how well it deals with stress not orthogonal to the treat surface, e.g. in cornering or side-skids.