So it looks like Rizoma Reverse Retro Bar End Mirrors you need an adapter to replace bar wts. With the plastic spacer they won’t fit the stock bar wts. With out the spacer they will, but looks like to much gap. What are the plastic spacers for? Could thread tape be used instead of the spacers? Really don’t want to spend another 90ish on adapters. Plus worried with out the bar weights there will be more buzz in the bars.