Recently decided to replace the rear derailleur on my 2020 Kona Honzo. I bought a 12 speed Shimano Deore M6100 SGS. Also got a new shifter to replace the stock Sram one.
Been trying to set it up for days now, but really can't get it to work perfectly. I've watched so many videos on how to set up a derailleur (Including the Park Tool one which was amazing), and I think I got the limit screws and barrel adjuster set pretty good now, because shifting works alright on all of the other cogs, other than the second largest (second smallest gear). When shifting down from third largest cog to the second largest, the derailleur cage will rub against the second largest cog. When shifting down multiple gears with one press of the lever, it will violently get stuck there.
B-limit screw is almost maxed out and it won't fix the problem still. I'm starting to think that maybe the chain is too long? Is it possible that if I change only the derailleur it would require a shorter chain? The chain itself is pretty taut, but if I pull it, the cage obviously extends and gets farther away from the cassette, which is what would solve my problem. Can I try this and see if it works? I haven't worked with chains myself that much, so could I take a couple links out and then put them back if it wasn't the chain?
Other possible culprits in cases like these could be too much housing, ie. a huge loop just before the derailleur, but my housing should be fine since I cut it like for like with the older housing. Other one I've heard is mismatching derailleur cage, but the one I got is a long cage version (SGS) designed to handle up to 51 teeth cassettes, and the one I have is a 50 tooth. This is driving me crazy, what can I do?