Then mine is in fact a ridged mount... Thank you kindly Longhair.

 

I had detachable mounts, sissy bar and luggage rack given to me. Installed rigid mounts instead (the detachables on my sportster rattled) and the sissy bar and luggage rack fit fine. I also have a Sundowner seat and appreciate the clear tubing idea as mine will definitely rub the seat and I'm not taking them off once installed. I had to manuver my sissy bar a little to get it in the mounts but a second person pushing the mount in slightly and it went in fine. No pictures yet but once I put the tubing on and permanently mount the bar and rack will take some. I may need a offset screwdriver to install the screws on the the sissy bar mount because at the bottom not much clearance because of the Sundowner seat.

 

I'll have to take a good couple of pictures of how my mounts are, because my detachable just does not rattle.