So, I owned a shop for ten years, and worked as a wrench for 20. I have worked on thousands of bikes...I have a brand new Cassette, Chain, and chainrings (9 speed, 11-32). Skips like a son of a bitch in ONLY the 11 tooth cog. Try it Nao has been...tried. Derailleur bscrew is perfect, spring is good (was working perfectly with the worn out cassette and chain). Anyone? CX bike.