The front pair are wider to accommodate BOTH the sissy bar AND the rack. The rack uses all 4 points of the docking hardware and the sissy bar only the front 2 and the shock mounts.
Edit to remove quote after re-reading it.

 

Mine was off about an 1/8"-1/4" (yeah, yeah, 5/16") adn I thought maybe I had something wrong, so I read the instructions that came with the sissy bar upright. It says something to the effect that minor adjusting may be needed. I just kept adjusting until it slips right on and off.

 

You are correct! I misread your post.

 

yes percisely, there is only one set of docking points that can be used with the sissy bar.

 

I'll bend it out I guess. And yes, I'm using the shock posts for the front. But the back isn't spread out wide enough to latch on. I thought I had installed the 4 point incorrectly but I guess it just needs some massaging.

 

When you put on the docking hardware did you remove one bolt from the bike? I know I tried to put my mounting hardware on leaving that bolt it place and it did not work right. It doesn't seem right that you have to bend anything.

 

I did remove the bolt yes. They line up nicely on both sides. But the sissy bar isn't wide enough on the back side to clip in.

 

Once you get it on leave it on the bike for a month or so. After that it will be easier to install.

 

Didn't have a problem with mine on my 2010 FLHX. Guess i just got lucky with a good fit!

 

Played a little tug of war with a friend using the sissy bar. Now it's mounted and is nice and snug. I read a couple of posts from guys complaining about rattling and there's none if that. Thanks guys.