Looking for some help here. I am upgrading Shimano Acera 8 speed rear derailleur to 8 speed Shimano XTR rear derailleur and it appears that because the old 8 speed XTR derailleur has a clip for the tension of the b-screw that keeps the derailleur from sitting flush and looks like it is not compatible. What am I missing here? Is it a compatible swap?

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    Welcome to Bicycles SE. Please add some clear pictures of both rear derailleurs with notations showing the interferences you are predicting. Edit your question to add the images. This will help us out and help you get a meaningful, accurate, and useful answer that others can benefit from as well.
    – Ted Hohl
    Jul 11, 2023 at 17:12
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    Hello and welcome - I imagine it would be fine, but definitely need a photo to show what you're up against.
    – Criggie
    Jul 11, 2023 at 19:27
  • thank you all i got it working the issue was with the crack alignment when i changed over to threespeed xtr hollowtech from the cheap octalink that came on the bike
    – XTR23
    Dec 7, 2023 at 17:00
  • @XTR23 Can you post that as an answer, not a comment? It's perfectly acceptable to answer your own question here. Dec 13, 2023 at 15:53

1 Answer 1


Many higher end Shimano derailleurs have had the circlip in question to allow disassembly and maintenance of the pivot bolt. RD-M900 (8-speed XTR) is one of those. In some (maybe all, not totally sure) of these designs the circlip will be the thing that rests against the frame, that's normal.

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