Tires and Wheels Pair of Caster Assemblies, 8 X 1 Inch, 8-spoke Black, Grey Rubber Tires, 5/16 Inch Bearing, 1-3/4 Inch Hub for Quickie Powerchair Wheelchair Review Posted on July 20, 2018November 7, 2018Author Marauderby Pair of Caster Assemblies, 8 X 1 Inch, 8-spoke Black, Grey Rubber Tires, 5/16 Inch Bearing, 1-3/4 Inch Hub for Quickie & most other Powerchairs or Wheelchairs with 5/16″ axles.