Abstract: A wheel-and-tire apparatus having at least two coaxially mounted tires is disclosed in which the diameters of one or more of the tires in the apparatus may be adjusted to select the tire or tires which are to be in contact with the road surface. The apparatus facilitates the selective use of tires having different performance characteristics, as may be desired or preferred to suit particular road conditions or vehicle operating conditions. The diameters of particular tires are increased or decreased as required to achieve a desired configuration of relative tire diameters, using tire diameter adjustment means such as one or more pneumatic pumps mounted in association with the apparatus. Sensors monitor selected operational parameters of the vehicle and transmit corresponding signals to a computer which selects an optimal tire configuration to suit the particular combination of operational parameters received from the sensors.

Abstract: A wheel-and-tire apparatus having at least two coaxially mounted tires is disclosed in which the diameters of one or more of the tires in the apparatus may be adjusted to select the tire or tires which are to be in contact with the road surface. The apparatus facilitates the selective use of tires having different performance characteristics, as may be desired or preferred to suit particular road conditions or vehicle operating conditions. The diameters of particular tires are increased or decreased as required to achieve a desired configuration of relative tire diameters, using tire diameter adjustment means such as one or more pneumatic pumps mounted in association with the apparatus. Sensors monitor selected operational parameters of the vehicle and transmit corresponding signals to a computer which selects an optimal tire configuration to suit the particular combination of operational parameters received from the sensors.