The two extremely springy tires in the Tamiya 70096 off-road tires set are about 50 mm in diameter and 30 mm wide. Use these if you want your robot to have a soft, air-cushioned ride across rough terrain. (Compatible with the Tamiya gearbox numbers 70093, 70097, 70103, and 70110, 70167, and 70168).
The Tamiya 70096 off-road tires set includes the following:
(The hex shaft inserts directly into the wheel with a tight press fit; no tools are necessary.)