Roomba 550 bumper doesn't move freely enough, causes circle dance and error 9. Are there supposed to be white plastic skids/sliders? : r/roomba
iRobot Roomba 550 - YouTube
Replacement Front Wheel Caster Assembly for iRobo t Roomb a 500 600 700 800 Series 527 529 550 560 570 580 595 620 630 650 760 770 780 790 870 880 980 (1 PC Front Wheel) : Amazon.ca: Home