Originally Posted by
SamSam77
If I understand you correctly, the different geometry and movement style of the 592 derailleur results in a larger pulley wheel / cassette gap than typical (and larger than what I had before with the 591), which means there is a little extra slack in the chain at this critical point. So when the derailleur tries to pull the chain to change gears, it cannot get quite enough movement to make the change cleanly/completely. I probably compensate for this by adjusting (biasing) the cable tension so that at least one shifting direction works alright, but this results in the other direction being worse off and thus producing the shifting lag going to the other way.
This is exactly my experience with it, yes. And I found the problem to be worse with cassettes with wider ranges. The larger the big sprocket, the more you have to tighten the B screw to keep the jockey wheel out of the sprocket. But that just means that you get really big gaps as you move down the cassette. This worked okay with friction shifting because you could overshift slightly to get the shift and then bring it back in line, but I really do prefer indexed shifting and I just couldn't get it to play very nicely.
I've read similar comments from others with their experience with these derailers, so I think this struggle is not specific to me or my bikes.
Having said that, it does appear that your cable routing is on the wrong side of the bolt. As others have noted, it can change the "pull ratio" of the derailer, so you get more or less derailer movement than intended, even if it's only slightly. Fixing that may or may not fix your shift quality, but you definitely want to start with as close as possible to how Shimano designed it.