Originally Posted by
Atlas Shrugged
That’s great. I “upgraded” my 9150 RD with the longer cage from a 8100 and increased capacity of the derailleur. That worked so well I did similar to my RX810 where I mounted a med cage from a XT. They were direct swaps so nothing as complicated as you performed. Enjoy.
Great to know and thank you for sharing!
I looked at R9100 derailleur outer cages (online) and they are a different design than 9000, which is unfortunate. I am a fan of direct swapping as well.