I read an article on the airless tires. They seem like a pretty good idea, but I don't know. They look like tires for a Bobcat, or a small front end loader. They looked tome like they would be kinda squishy for making any turns, especially at higher speeds.

I could not see the 'glass leaves lasting very long. They might work great, but I really don't think they could handle even half the abuse a steel leaf can.

There is a reason I never buy hammers with fiberglass handles. The 'glass can shatter on non-direct impacts. Just think of an axle drooping onto a rock; that vibration from the impact could shatter the 'glass leaves without the leaves actually hitting anything. Just my 2ó.