"Getting a puncture is one of the most frustrating things that can happen on a bike, so the rise in the prevalence and quality of solid puncture-proof tyres is welcome. Made from sturdy “mircro-closed polymer resin”, they never burst or even go down, so require minimal maintenance. The tyres can happily roll over nails, glass and potholes, making them ideal for heavy wear and locations with poor road conditions. The only downside is that, although they’re surprisingly light, they’re still much heavier than rubber and air. The technology isn’t quite there yet, but we’re approaching a point at which solid tyres may be a competitive alternative to pneumatic ones."
Quote from: https://www.theguardian.com/cities/2017/jun/17/10-best-cycling-innovations-dockless-bikes-solid-tyres