no. there are some hanger geometry issues with some of the 12spd stuff. but shimano 12spd did away with the direct mount hanger entirely. it's gone. I've seen more problems with ppl who had direct mount 11spd derailleurs trying to install shimano 12spd and having trouble finding NON-DM hangers for their frames.

my first question to you is going to be related to chain length. you've gotta be pretty detailed to make sure you choose the correct chain length. How did you measure the new 12spd stuff?

 

Plus 4 links after you measure the chainring-biggest gear on the cassette.

 

With further adjustment I am able to make the derailleur shift smoothly. But, there is no B-Screw adjustment available. The B-Screw is backed all the way out and the derailleur cage is lower than it should be in reference to the Shimano guide mark (in the section Adjusting the SIS). That tells me that a 50t cassette is the largest that this derailleur will support.

I could remove some material from the stopper plate that the B-Screw rests on. That would allow more adjustment. But for now, it works well.

 

What cassette are you running?

I have a 12 speed Shimano derailleur but am running it with a 50 tooth cassette. With this setup and proper chain length, there isn't much adjustment left, but it works.

:edit: in regards to your post above, I think you are thinking about the b-screw adjustment backwards. You need to unscrew it more, as you're running a smaller cassette than what Shimano 12 speed is designed for. So you need to run the derailleur even closer, thus backing out the screw. If you put a Shimano 51 tooth cassette on you'll most likely have to screw it in more. Maybe I have it backwards? Who knows.

 

I am running an 11-50 Sunrace cassette. There was no way to adjust the B screw in any direction to get the derailleur cage closer to the 50t cog on the cassette to get enough chain rap to help the chain shift on and off smoothly. I solved the problem by installing an 11 spd Shimano XT derailleur. It shifts now. Not as good as I would like but much better and more consistantly than the 12 spd SLX derailleur I had before.

At this point, I am waiting until I wear out this 11spd drivetrain and then I will upgrade everything at once.

 

wait. you were trying to use a 12spd derailleur on an otherwise 11spd drivetrain? no wonder it wouldn't work.

 

Shimano 12spd ders work fine with Shimano 11spd cassettes (w/Shimano 11spd shifters.)
=sParty

 

obv not for OP

 

Evidently.
But works perfectly for me.
I learned about their compatibility right here on these very forums.
IIRC it was @huckleberry hound that informed me... I could be wrong.
=sParty

 

I inadvertently left out the brand of cassette in my OP. I am using a Sunrace, 11-50t, 11 spd cassette. That must be the limiting factor with my issue.

 

could be. the last sunrace cassette I used was the 11spd 11-46 and it worked quite well. have not used any others since, but this is also not the first time I've heard of a drivetrain set up with a more recent sunrace cassette shifting poorly.

 

My Sunrace 11-50T shifts like crap. And I have to shift 3-2-1-2 to get it into second. One of the few things my shop guy has given up on in the 4 years I've been going to him. YMMV.

 

^ I won't say mine shifts like crap, but it does not shift as well as a Shimano cassette. When shifting up the cassette, I have to hold the lever for a few seconds to help the chain complete the shift.

 

I had a similar problem with the Transition Smuggler derailleur hanger. It was not compatible with Shimano 12-speed derailleurs. Transition changed it. Derailleur can now pivot more forward. You can file the derailleur hanger to fix it. More details here

So I played around with 12 speed SLX rear derailleur...

My wife's bike is set up with an 11-52 chinese 11-speed wonder, courtesy of ZTTO excellent warranty policy :) It was being shifted with an 11 speed SLX shifter and RD-M6000-GS Deore rear derailleur. It kind of worked, but was far from 'click->shift' kind of performance. I mean - I can get around...

www.mtbr.com

 

I have XT 12speed RD with a 12 speed Cass 10-51t and it shifts perfectly fine, i have b limit tension adjustments available if needed. im running a Prim v3.2 frame.