@DaddyCoolI've done a few versions of these caps. At first I removed the end cap in the DOM peg (it's screwed in but has some pretty strong loctite.). I was able to get the threading to work but, I had a hard time keeping the nylon from loosening on me. I thought about gluing them in but, that would make removing the back wheel a chore and would more than likely ruin the peg caps.My current solution is pretty much like bar ends. I actually used the set screws from some bar ends to keep them installed. This design also has the cap sitting over the original peg cap. It's slightly recessed to try and have the slight rounded end cap of the DOM peg sit inside my cap. I tried to show that in the image attached.This is probably about my 8th or 9th attempt. So far they work pretty well! This set is probably 3 or so months old too and while getting worn down they're still doing their job!