A little more explanation to what BeemerDonS posted.
The Ilium bars have a top cross bar that goes across the front of the motor. The side bars slip over the ends of this top bar.
The top bar is threaded (6mm x 1mm) to accept a bolt that goes through the side bar to hold it to the top bar.
When we finger tight assembled the bars to the bike, the 6mm bolt jammed up after only about 2 threads were in. The suprising part was that the bolt would not back out. So we used a hex key to try to back it out, but it wouldn't budge. Finally, in frustration, the hex key socket on the wrench came out. That actually broke the bolt, leaving the 2 stuck threads part of the bolt in the cross bar.
After much effort on the drill press, we removed the bolt remains. Time for re-assessment !
Looking at the crossbar, I think we found the problem. It looks like the tapped hole in the crossbar was not protected when the bar was powder coated. When we tried to thread the bolt in the other side of the hole, it would quickly snag up. The powder coating seems to catch the threads and snag the bolt.
So, I broke out the 6mm X 1mm tap and chased the threads in both holes. After that, the bolts went in easily.
So, the warning is - clean out the threaded holes in the crossbar before you start assembling.
Note to Ilium - that threaded hole should be capped during powder coating.
Other than that - the rest of the assembly went without a hitch, and the bars look great and the highway pegs are sweet.