How can I create a saddle that can alter the Dino's BP values?

Now I’m trying to change the collision preset for the mesh, but it’s not working correctly:

https://dl.dropboxusercontent.com/u/8512731/ARKDevkit/Ankyl1.jpg

I’m trying to make the mesh ignore other dinos like Raptor etc. has. The above thing works at first, but when I exit the Ankylo and ride another one with the same saddle the collision is returned to normal. Somehow it’s not keeping the new collision setting I make.