Lite Flites
From Combat Robot
Dave Brown Lite Flites are lightweight foam rubber wheels designed for RC aircraft. Like many other parts currently used in combat robotics, they're a great carryover.In combat robotics, they're used in the smaller insect classes, the Skeeterweights, Antweights, and Beetleweights.
They have a snap-together light grey plastic hub with an 1/8" bore. There is a chart of general sizes at the Dave Brown site:
