Airless tyres. Something that could be developed for bikes?

Mind you, bicycle tyres can't use the same kind of flat profile that car tyres use though, so maybe it wouldn't work for cyclists. :-(

I can sort of imagine a complex three dimensional mesh that compresses in all directions. But I cant see it being anything more than an engineering folly as it would be ridiculously difficult to design and manufacture.

The tyres on that bike in the promo vid do not look good at all. They are well stiff, not deforming around the boulders at all. But if you made the flex greater, they would squirm laterally like nobodies business.