A wheel support assembly is mounted to a pivotable system spanning an opening, with the pivotable system mounted to one side of the opening at a pivotable connection and to another side of the opening at a removable connection. The support assembly is disposed proximate the removable connection and spaced apart from the pivotable connection, and has a wheel positioned and oriented to support the pivotable system weight that would otherwise be cantilevered as the pivotable system rotates about the pivotable support. The wheel support assembly may include a vertically adjustable wheel that may be adjusted to remain just out of contact with the support surface when the pivotable assembly is connected to both the pivotable and the removable connections.