I have those on my 2015 Polaris 570. I can carry my Excalibur crossbow with no problems I also use them for my win 30.06 , Ruger American 308 , T/C Encore and Browning , Mossberg shotguns. They support all of the firearms securely.
I have an old 500 with a flat front rack. I just put a blanket down and lay my old Excalibur flat. One rubber bungie across the rail and one across the stock at the grip. Doesn't move and in 3 years has not made a mark on my xbow.