A retractable wheel assembly includes a wheel frame supporting a wheel, and a pivot bracket assembly secured to the wheel frame. The pivot bracket assembly is displaceable between an extended position and a retracted position. A biasing mechanism is coupled with the pivot bracket assembly. The biasing mechanism urges the pivot bracket assembly toward the extended position when the pivot bracket assembly is in the extended position and urges the pivot bracket assembly toward the retracted position when the pivot bracket assembly is in the retracted position.