Abstract: A convertible wheelchair system, between a wheelchair configuration and an all-terrain configuration, is provided. Embodiments include a central frame aligned along a central longitudinal axis, the central frame having a front and back bar parallel to each other and orthogonal to the central longitudinal axis, paired side bars aligned with the central longitudinal axis, and paired wheel cages, aligned with the central longitudinal axis and attached to the front and back bars, each wheel cage supporting an axle and a wheel mounted thereon. The system further includes a forward beam alignable with the central longitudinal axis, configured to support a forward wheel, and reversibly attached to the front bar. The convertible wheelchair is in the all-terrain configuration when the forward beam is attached to the frame, and the wheelchair configuration when the forward beam is detached from the frame, the central frame thereby standing without the forward beam.