An upright surface treating appliance includes a main body having a user operable handle, and a support assembly for allowing the appliance to be rolled along a surface using the handle. The support assembly includes a yoke pivotably connected to the main body, and a pair of domed-shaped wheels rotatably connected to the yoke. A surface treating head is connected to the yoke. The yoke is shaped so that a section of the yoke is located between the rims of the wheels. To afford a compact appearance to the appliance, the outer surfaces of the wheels and the section of the yoke together at least partially delimit a substantially spherical volume.