Wheeled riding vehicles, including tricycles, with extremely thin stowed profiles are provided, which in one embodiment, include movable, collapsible tires/wheel axle assemblies, as well as folding frame parts and a unique handle that is removable and stowable within the vehicle frame when not used. The riding vehicle hangs totally flat on the wall, or fits in car trunks easily. One version is pedal powered, and a second embodiment provides for an integrated propulsion linkage providing for battery or motor power to the rear most wheels when they are moved into their operative position. The rear tire wheel assemblies also may be stowed and folded compactly inside a rear storage compartment with a lid.