Abstract: A convertible carriage having a wheel retraction mechanism to provide biased wheel retraction. The carriage has a superstructure including a seat for carrying a person to be transported, a plurality of wheels, and a plurality of leg members pivotably interconnected with the superstructure for rollably supporting the wheels to transport the superstructure when leg members are in an extended position below the superstructure. The carriage further includes a drive mechanism for relocating the leg members between a retracted position and an extended position, and a biasing mechanism, connected to the drive mechanism, for driving the leg members to the retracted position. The drive mechanism loads the biasing mechanism when the leg members are driven to the extended position. There is also a mechanism locking the leg members in the extended position to inhibit retraction by the biasing mechanism.