PURPOSE: To brake a car so effectively in a simple structure by installing a ringextending part more outwards than a tire setting position, in a rim of a tire wheel in the car wheel, and setting up a braking mechanism in this section.

CONSTITUTION: In this motor car equipped with a a boarding seat or the like in a body frame being supported by a single front wheel 2 to be controlled by a steering handle and a symmetrical pair of rear wheels to be driven by an electric motar, the front wheel 2 is soconstituted that a tire 13 is installed in a rum 12 of a tire wheel to be attached tight to an axle shaft 10. A ring extending part 12A extending to the left is installed in the rim 12 at the left out of these symmetrically paired rims 12 and 12, and a pair of brake shoes 16 and 16, being pivoted at symmetrical bode sides free of rocking motion so as to make possible to contact or separate to or from each other, are installed in this ring extending part 12A. These brake shoes 16 and 16 are pressed to the ring extending part 12A via a control wire 15 being pulled in the case of drawing the brake control lever, thereby controlling the front wheel 2.