I've just fitted a 11-42t cassette and initially a RD-M4120 rear mech, which does not have a clutch. This shited fine, but was prone to dropping the chain and very noisy.
I found a RD-M6000 clutched mech, which does clear the 42T with the B-tension most of the way in, but that leaves the top jockey a long way from the 11T at the other end, giving poor shifting at the lower end of the block.
Does a Goatlink help with this? ARe there any decent copies out there that move the mech backwards, rather than the cheap ones that only seem to lower it - that would just make the issue worse.
I found the Sunrace Extender Link (SP570) improved the shifting of a wide range 10 speed setup.
I’ve used the sunrace extender on a couple of bikes and it’s worked really well
3rd for the Sunrace one...
I fitted it and let the b-tens back out and it just worked
caveat ... it's going to really depend on your existing mech hangar to some extent..
Advice received! Just ordered a cheap sunrace copy of Amazon, cos I never learn my lessons and feel cheap today. Will report back here with the results.
Most, not sure about all, goatlink type extenders can be angled backwards or forwards if you need a bit of leeway between jockey wheel and big sprocket.
The issue with the M6000 (and lots of other mechs is the lack of offset of the top jockey meaning it doesn't rotate in close enough as you shift to the smaller sprockets.
Strangely enough shimano seem to have rediscovered offset upper jockeys for the latest gen of 12 speed (which is the same cable pull as 10 and 11)...
Clutches don't do that much more for chain Retention anyway (IMO/IME), are you sure it wasn't a knackered N/W ring or too long a chain causing your chain dropping issues with the 4120 mech?
Soo... Workstand test is promising. Now it's fitted I can see that dropping the mech slightly gives the clearance for the 42t, so you can then unwind the b tension to allow the mech to wrap around more and close the distance to the 11t.
Might WFH tomorrow so I can test it out on the trails.
Final results are in - it works! Thanks for the advice all.
