Tires and Wheels Invacare Caster Assembly, 8 X 1 Inch, 8-spoke Grey, Grey Rubber Tire, 7/16 Inch Bearing 2-3/8 Inch, Hub for Invacare Powerchair Wheelchair Review Posted on June 6, 2018November 7, 2018Author Marauderby Invacare Caster Assembly, 8 x 1 Inch, 8-Spoke Grey, Grey Rubber Tire, 7/16 Inch Bearing 2-3/8 Inch, Hub for Invacare Standard Powerchairs Wheelchairs.