Lightweight tire support and composition and method for making a tire support

A method of preparing a lightweight tire support, said method comprising:

• (A) injecting an isocyanate-side stream into a processing mold designed to mold a tire support, said isocyanate-side stream comprising at least one isocyanate;
• (B) injecting a polyol-side stream into said processing mold, said polyol-side stream comprising at least one polyol and at least one chain extender;
• and
• (C) reacting said isocyanate-side stream and said polyol-side stream in said processing mold to form a tire support, said tire support comprising a hard-segment polymer and a soft-segment polymer, said soft-segment polymer and said hard-segment polymer being present in an amount effective for providing said tire support with temperature stability and load-bearing capability, wherein a gas is dispersed in the isocyanate-side stream, polyol-stream or combination thereof such that lightweight tire support has a microcellular structure.