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Having a real pain with this one, was out today and it just wasn't shifting out of the big ring after climbs, then if i bunny hopped or slammed the rear wheel it would then move. Got home and stripped down the bike, it's the 11sp XTR mech with clutch, seems to be more of an issue with the clutch on so i took that apart, all is normal, same with no bending of the rear mech/hanger. Tried it with a new cassette and chain, same issues showing through.
So, what i have now is shifting that works until the last 3 sprockets, then it jumps one, i fix that and when i get to the last 3 at the other end it jumps, no matter what i do it is out on one end (big sprockets or small), i've had a tweak of the b tensioner, set up as per it should be, set up the high/low tensioners as well, they're fine, so all i can think is something is just wrong with the mech, i changed the cable last week as well, so struggling to work out what the hell is going on, anyone had similar?
Sounds like the hanger and / or the mech are twisted. Have you checked the hanger with a tool or just visually?
edit: have you clamped the cable in the right place?
Sounds like the mech or hanger are bent (indexing being out at one end of the cassette or the other)
Could also have a separate issue with the clutch, you can clean/grease and set the torque.
Per above - definitely sounds like bent hanger. I'd replace it even if it doesn't look bent. Even a slight bend that isn't visible to the eye can still cause shifting to be off, and especially the issues of "works at one end of the cassette and not the other".
You could also double check that the derailleur cable is correctly routed the whole way along the bicycle, especially if it has an "under the BB" guide. A friend of mine once routed it on top of the guide plastic instead of through it* when replacing the cable, and took several days of tweaking shifting adjustments to realize this.
*It was me, actually
I'd replace the mech hanger with a decent aftermarket CNC machined one from Pilo or Wheels Manufacturing. Also, have you checked the rear mech cable isn't causing issues?
Checked the hanger, 100% true, it's off a transition patrol, but will get one as been looking to get a spare for a while, also lubed up the clutch, it looked fine but might as well give this a last try as per the advice above, failing that i'll be sticking the other mech on from the hardtail to check, or just leaving the clutch off!
In that case it might be worth backing off the tension from the clutch a bit. I always index and tweak cable tension with the clutch disengaged until it is perfect, then engage the clutch and dial on enough tension so that the chain tension is good but the derailleur will go through the gears with no dramas. Its a super easy job on Shimano 11 speed stuff as it has the externally adjustable clutch (at least my XT does).
Cheers, did that, nice shifting without the clutch, just when it's engaged i get that stiction at the top, have put a bit of oil in and around, will do that again to make sure it's penetrated and have wound down the clutch tension as well, as it's on a full susser anyway. Here's hoping it starts working, i've got two trips to BPW this week!
I've had similar with an SLX mech, everything set right, new cables etc. and with the clutch on, would not shift of the biggest sprocket.
I asked on here and was told by 3-4 people that it was a cable issue, even thought inner & outer where new and moving freely. So I shifted into the biggest sprocket and undid the cable from the mech, still wouldn't move.
It's now being run with the tiniest bit of tension on the mech as it's the only way it'll work.