I have a Bacchetta Idler Bolt here. Better image from Bachetta. My issue is the Idler bolt is too long and is causing my Idler to go back and forth, which was fine when I had a cassette, but now I have an IGH, and I don’t need it to slide. The sliding is causing my chain to pop off at the chainring. If I had a smaller Idler bolt, it would not slide.