A rack includes a chassis, and a plurality of wheel assemblies secured to the chassis. Each wheel assembly includes a bracket, a wheel, and a handle. The bracket is rotatable relative to the chassis between a first position and a second position. Each wheel is capable of rotating about an axis. A distance between the axis and the chassis when each bracket is in the first position is less than a distance between the axis and the chassis when the bracket is in the second position. The handle is secured to the bracket and configured to rotate the corresponding bracket, and extends inside the chassis.