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Sooooo what embarassingly simple error have I made?
Di2 R8050 mech on 11-34 cassette is basically one gear 'out'. With the digital trim at 0 it won't shift onto the biggest cog, and will shift past the smallest cog and drop the chain. If I max the digital trim this only just bumps it to the right gear, but is still a bit noisy and obviously a bit of a bodge.
It's as if the cassette is one gear too far towards the hub, however there's no play in the cassette and the 11t is flush against the lockring. Mech hanger is aligned as well.
Process of elimination leaves me with some sort of hub spacing (Hope RS4 with 142x12 adapters) or mech issue. I'm pretty stumped though 🙁
Is the hanger aligned correctly?
Have you tried the upper/lower stops.
No idea how they work on Di2.
Is this a new install or a messed around with previously working set up?
with Di2 you set the indexing 1st then set the stops at the end of the procedure. Follow the Shimano set up guide from the start again and see how that goes, it’s never failed to work on any of the Di2 installs I’ve done.
Hanger is aligned using tool - I'll get a second opinion from shop on Monday if no luck though.
I can tighten the high limit enough to stop it dropping the chain, but the software shows an error because the adjustment is too big and it starts impeding the mech.
New install. I've been following the guide, but when I use e-tube to put it into the 5th cog like it says, it's actually sitting in the 6th.
Have you got the correct cassette entered on the software?
Yes I've set up the synchro shift for 11-34. Still no dice :/
Might be a daft suggestion, but what about simply lifting the chain off the cassette and moving it one sprocket across to where it should be. Then adjusting from there?
Back to basics.
Does the RD index and align across the cassette without the chain?
Can you borrow a wheel with same cassette?
Any error messages on the software?
Have you tried a system reset?
(Cant believe its come to 'have you turned your bike off and on again?')
Looking on with interest as I shall be trying to run an XT group set with Ultegra shifters soon.
my XTR did this, i could never work out how to fix it, resetting the whole system did nothing,
Eyeballing it with the chain off it doesn't look too far out, but it's definitely sitting beyond the 11t.
Only error message I get is if the high limit is too tight and it prevents the mech from doing the little overshift wiggle. The limit screws don't appear to alter the index point with Di2, just stop the chain from dropping off the cassette.
Unplugged everything and left it for a few hours, but it hasn't forgotten any settings or 'reset'. Assume there's another wee battery in there somewhere? Ran the crash reset mode but that doesn't fix anything.
Tried a different wheel (Pro 4) with same result. It's almost as if the driveside end cap is a few mm too wide, or the mech hanger is a few mm too thick. Either way I think it's a shop job 🙁
Have a read through this and see if anything is similar to your problem
https://www.bikeradar.com/forums/viewtopic.php?t=13082850