Abstract: The object of the invention is to provide an anti-sway stabilizer (20) that is pivotally connected to a support arm (26) of a vehicle bike transportation rack, making available a convenient attachment of a bicycle top tube to the support arm for prevention of a bicycle held on the rack from swaying to and fro when subjected to over the road vehicle movement. The anti-sway stabilizer consists of a rubber bike separator cradle (22) that includes a bore (24) therethrougth that slides over the vehicle bike rack support arm and has a thru-hole (28) parallel with the bore. A pivoting stabilizer member (32) in the form of a yoke (36) is rotatably attached to the bike separator cradle with a screw (40) and nut (42). An attachment strap (48) secures a bicycle top tube to the bike separator cradle and a second attaching strap (48) secures a bicycle seat tube or down tube to the stabilizer member.