Help with Di2 Rear der.

[oldguy00]

Hi all, I have one of the newer Ultegra long cage Di2 rear derailleurs.

I have the shifting tuned up great -except- that it doesn't want to stay in the hardest gear. Any time I shift into the 11, it wants to jump up into the 12.
Otherwise it shifts perfect all throughout the cassette and chain looks centered in between cogs.
And, I have the limit screw (H, I think) backed out all the way already.
I'm using an Ultegra 11 speed cassette, and I've tried two cassettes.

Help!

[Geekonbike]

I'd check the derailleur hanger....could be slightly tweaked.

[Blown Reek]

You might need to go and adjust the individual cog's chain location via the E-TUBE app. And make sure you're adjusting the correct limit screw.

[stien]

Have you tuned the shifting? Hold the junction button until it’s red, then press right side small shift lever to increment the shifting in that direction a few times, hold junction button again to exit.

[oldguy00]

Thanks for the replies.

Its a Felt IA FRD, and does not have a bendable/replaceable hanger, and the frame is basically new. Hopefully it isn't out of alignment.
I haven't used the etube app before, but yes, I have tuned the shifting via the junction box. Again, all the other gears seem to be shifting well and chain looks centered between all gears. And yup, have the correct limit screw backed out.

Kind of wondering if for some reason the alignment is slightly too far off between the crankset and the hardest gear in the back? Almost seems like the chain is skipping off the top of the cog, not sure.... I'm using a dura ace crankset with AB chainrings and Wheelsmfg conversion outboard BB (frame is bb30).

[SPOKE]

Is the correct diameter cassette locking installed? The 11t cassettes use a smaller diameter flange up against the last cog.

[oldguy00]

Yup, using the 11 speed lock ring that came with each cassette.

[oldguy00]

OK, so I took the chain off, which happened to be a very expensive wipperman, and put my backup KMC chain back on, prob seems to be gone.
Did a little research online, and it sounds like I probably had the wipperman quick link installed backwards.
Just packed the bike up for Mont Tremblant 70.3 this weekend, so will have to wait until next week to see if I'm right.

Thanks all.

[CiclistiCliff]

FYI, hanger can be aligned. Those IA/B/DA series had some stout drop outs. Also, make sure the wheel is straight in the frame. Those drop outs are adjustable.

[BdaGhisallo]

OK, so I took the chain off, which happened to be a very expensive wipperman, and put my backup KMC chain back on, prob seems to be gone.
Did a little research online, and it sounds like I probably had the wipperman quick link installed backwards.
Just packed the bike up for Mont Tremblant 70.3 this weekend, so will have to wait until next week to see if I'm right.

Thanks all.

Flipping that Wipperman Connex link over and installing it in the correct orientation will definitely make a big difference.

[oldpotatoe]

Flipping that Wipperman Connex link over and installing it in the correct orientation will definitely make a big difference.

Yup, upsidedown and it acts like a 12t lockring on a 11t cog.

[oldguy00]

Yup, upsidedown and it acts like a 12t lockring on a 11t cog.

Yup, thats what I found on Dr Google. :)