The present invention provides a wheel retraction assembly that can be used with a convertible cart for transport of cargo. The convertible cart includes a support structure, first and/or second wheels, each with a retraction assembly that includes telescopic and fixed struts. The wheel retraction assembly is operatively associated with the support structure and is movable between retracted and expanded positions. One end of telescopic strut mounts the wheel axle structure and the opposite end is connected to the support structure. In the retracted position, the wheel retraction assembly maintains the first and/or second wheels in a position to enable the cart to be moved. In the expanded position, the retraction assembly moves the first and/or second wheels to another position to be adjacent the support structure wherein the wheels do not support the cart. The cart also features a convertible handle assembly and a mountable platform.