Ultegra r8050 Di2 micro adjust maxed out

Just installed ultegra r8050 and have a weird problem. I have to set the rear derailleur micro adjustment to +16 (max) for it to work properly.

I think this happened after I went to front derailleur adjustment and the e-tube app jammed the rear derailleur against my trainer. I reset the rear derailleur and it’s got it working on that +16 setting.

Did I manage to bend something? Stupid there isn’t a safety setting when adjusting the front derailleur, I guess i was on the wrong gear.

Is your derailleur hanger bent?

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I would check this and then double check your limit screws since the RD shouldn’t be traveling that far. Usually you can get pretty close with the barrel adjuster and then fine tune it. Make sure there isn’t any cable snag or misrouting as well. I’ve had that happen a few times where the cable path wasn’t going where I thought it was
edited to accommodate my poor reading comprehension

The 8050 is di2 so the +16 is a fully maxed out on the barrel adjuster if compared to mechanical.

oh, sorry, missed that this was electronic. Please disregard my cable references, but I would still double check hanger alignment and limit screws (I think di2 still has those)

Thanks for the suggestions. I guess I need to get a hanger alignment tool. It’s like it’s one gear too low and I have to fix it with micro-adjustment in max.

An alignment tool is nice to have, i am glad to have one on hand.

In the meantime though, when you do a quick visual check of the pulley/cog alignment at “0” and maxxed out, what are you seeing? Does anything look obviously bent or out of line?

When I’m at 0 I’m one gear lower than what e-tube app tells me. It does look like the lower pulley wheel is a bit closer to trainer than top one.

Looks about the same when maxed out just that it’s in the correct gear then.
It’s still not perfectly centered though running out of adjustment.

So I guess the derailleur hanger could be a bit bent in, which would make sense. The frame has fallen a few times and I bought it used.

Start over.

  • Shift to small ring in front and big cog in back
  • Take microadjust to the middle setting. It has 33 total, -16|+16
  • Adjust the B-screw to so it just doesn’t have the jockey wheel hit the big cog
  • Shift to the 5th cog from the top of the cassette
  • Adjust the high and low limit screws by backing them out a bit so they don’t get in the way of adjustment procedures
  • Get into adjustment mode
  • Pedal the bike and hit the button that goes to a bigger cog until you just hear the chain rattling on the next biggest cog
  • Press the button to go to a smaller cog five (5) times then get of micro adjust mode
  • Try shifting through the gears. You might need to fine tune but generally not from there.
  • Shift to the largest cog. Adjust the low limit screw to where it just touches the stop
  • Shift to the smallest cog and do the same thing except then back it off one full turn
  • Next step is front derailleur adjustments.

I’ve seen it happen where someone micro adjusted so far it skipped to the next gear and caused issues. You’ll want to go through these steps to make sure that isn’t the case. I have all the tools to check the hanger too so it could be that but I would check this first just to rule it out. The other things to check is make sure the hanger it installed tight and the cassette lock ring isn’t loose. Those two things can also cause issues like this.

Hope that helps. Here is the link to the manual if you don’t have it already: Manuals & Technical Documents

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All you ever need…

Oh and I agree, I’ve had the same problem and it was my derailleur hanger

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I’ve started over countless times. Tried setting it on first gear and removing the micro adjusts. It just tries to jam the derailleur against the limit screw, didn’t dare to go below +5. And then when I switch to 2nd gear it stays on first just releases the tension.

No amount of tuning is gonna fix that it’s physically 1 gear too low. I think I’m gonna need a spacer somewhere as a temporary fix.

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Shim out the derailleur or adjust the shims on the cassette. I’ve seen this problem on a couple specialized frames. One road and one TT.

To move the mech outboard, McMaster Carr has shims that will work. I loaned my packs to a buddy or would give you the numbers. Get a couple different thicknesses.

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Check your freehub documentation to see if you should have a spacer for the cassette you are using.

Ha…100%. I’ve had that happen too

In this case, the RD appears to be too far inboard, or the cassette too far outboard, so it would be a spacer that shouldn’t be there.

I assume Shimano has a spec for the expected horizontal distance between the hanger plane and the lowest cog plane?

I don’t think any 11 speed cassette needs a spacer.
I bought 2 millimetre washer from hardware store and installed it between the hanger and derailleur.
Re-adjusted the gears, rear derailleur is now at -2 micro-adjustments so almost center.
Seems to be working perfectly. I’ll still get my hanger straightened before outdoor season begins. I would prefer to thread the derailleur fully in.

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I’m pretty sure the 11-34 is intended to work with a spacer.

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Just double checking… are you 100% sure it is installed correctly?

Some users leave the B/B2-link plate on when they shouldn’t, or don’t align the tabs on the derailleur/hanger correctly. That can throw things off too.

If it works with a washer, then that’s OK. Some hangers are slightly out of spec (but not so much that the manufacturer would replace them) and this can happen. Shimano have told me that they sometimes use washers too.

Another forum success.

The hanger is likely straight. It’s a tolerance issue not unlike out of round BBs.

Happy shifting.

Yes, it comes with one.

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