Where Can I Find Replacement Black Knobs for My Bones Rack? Philip Cowles March 30, 2018 14:11 Follow Replacement rack parts, including Bones knobs, are available on our Replacement Parts page. Related articles I Need to Replace the Top Hold-Downs on My Bones Rack. Why Won’t the Replacement Rack Straps on the Accessory Page Work? I Am Worried That Trunk Rack Will Scratch My Car. What kind of bike (type and weight) can be carried on my bike rack? Can I Use a Cover on My Bike While It Is on a Saris Rack? What Are Hatch Huggers? Comments 0 comments Please sign in to leave a comment.