if you look at the BC ones here on the Bike in pic one, they are slightly pulled back from the collar, I suspect it may be because they are not notched as they go up a size, or because they are not dimpled and they thought putting the wires before the collar was the best option.
http://www.british-customs.com/triumph-america-speedmaster-radius-drag-handlebar-1-1-4.html I did try the bars with the notched out and it does work, but they forgot to do the holes before they welded them onto the risers
