To provide a tire wheel generating a large drive torque both at straight and curved road portions, and reaching high speed.

A mounting rim 1 has apex on the rotation axis outside of the rim 1 in the rotary axis direction. A tire is provided with a toroidal carcass with a pair of crowns ending at beads 23 facing in the axial direction, and connected to sidewall 22 so that the pair of crowns are engaged with corresponding based seats 11 formed on the rim, and has its maximum width in the bead area. An inner tube 3 is inserted into a toroidal cavity partitioned between a tire and the rim, and expands elastically by introducing liquid under pressure into its internal volume. No element connecting to the external environment of a wheel, especially an element extending through the wall of the rim exists in the inner tube 3. An expanding/contracting device inserted into the wall of the inner tube 3 is provided.