I need to clarify. It might slide maybe an inch in any direction. I just expected it to be tight against the seat like my Ducati bags were on my 1098. Now, with that, I have had it on the back for 5k miles of everything from twisties to high speed interstate runs and it is still there. I just put the expensive stuff in my little SW-Motech tank bag.Thanks for the input guys. I might stick to just using a backpack. If it's sliding around even with it being fully tight, that's not ideal :-/