So I removed my 11-34 Ultegra cassette to give it a nice clean and scrub. At the end I noticed the adhesive ring (https://dassets.shimano.com/content/dam/global/cg1SHICCycling/final/ev/ev/EV-CS-R8100-4861.pdf) came off. I noticed it was glued to the back of the big sprocket, but the glue must have been eaten away by my degreaser (diluted Zep citrus degreaser).
How fucked am I? I assembled everything back on to my hub including the adhesive ring. But obviously I did not glue it back to the sprocket.
