Originally Posted by
BirdsBikeBinocs
.... But I still have the question.... When exactly did Shimano do this.?? And who did it first and when.?? I'd like to know the details. Can you answer that for me or do you not know.??
Looks like @
dsaul answered you already: "Shimano introduced "Shadow" technology on XTR rear derailleurs around 2007. It's main purpose was to protect the rear derailleur from being damaged by rocks, trees, etc. They later added a clutch and named it Shadow Plus, but it was still only available on MTB derailleurs. It looks like it was introduced to Dura Ace and Ultegra rear derailleurs in 2017. "
I have a 2013 SLX 9-speed derailleur on my MTB and it certainly is a fine piece of kit.