>>1640871>You need a better external contact surface and inner structures to improve rigidness.Careful. Rigidness will typically reduce hysteresis by reducing deflection, sure. But generally speaking, you do NOT want a tire to be rigid radially. Radial compliance is essential for a wheel to roll smoothly over an irregular surface - so the goal is to introduce this compliance without an excessive amount of hysteresis.
Pneumatic tire casings DO have multiple fiber plies, which stiffen the tire in tension (allowing the tire to inflate without distending) while keeping it thin and supple in bending. When the tread of a pneumatic tire deflects radially, it does so by bending, with minimal tensile stretching or contraction; and the radial load is carried by pneumatic pressure. It is this combination of qualities that allow a pneumatic tire to be compliant over irregular surfaces while still maintaining low rolling resistance.
You CAN make a solid wheel that rolls quite efficiently, but only by making it extremely rigid - to a degree that it is only suitable for very smooth surfaces. Railway wheels are a good example of this. But for everywhere else, pneumatic tires are the most efficient form of compliant tire, bar none.
>Regular tires have steel wires, multiple layers of rubber, ...Bicycle tires don't use steel bands the way auto tires sometimes do; when steel is used in bicycle tires it's generally only in the bead, where the tire clinches into the (already rigid) rim. Even so, the steel bands in an auto tire serve essentially the same purpose as fiber plies - they stiffen the tire casing in tension, while remaining thin and flexible in bending. It's also worth noting that high-carbon steel has much lower hysteresis than any polymer or elastomer.
