For the record I'm having no trouble at all with the 592 on my Shimergo bike, now. I wasn't at first. I blamed it on my 27t bottom far below the rated minimum (36 coming soon, one thing at a time), and maybe a bent hanger. I did replace the hanger and it seemed to fix it. So maybe it's finicky about alignment. Its b-screw is all the way out to get the clearance close as I could, but it's still pretty far away.