Not sure but I think KST makes a mirror mount that drops those mirrors down so you can use the whole thing. I have 16 inch bars and can see my mirrors in stock position.
Looks great. I have 12" and had the same problem. TomA Is right. I bought the drop downs from KST and love them. I could only find (2) type of drop downs and KST was much cheaper than the other but good quality. Use lock tight.