Question: Shimano Di2 Rear Deraileur shifting issue

[weisan]

Would like to consult with the PL community on something.

So, I am changing out my gravel bike from 2x11, 11-34 to 1x11, 11-52.





Completed the installation earlier today, encountered some shifting issues outlined below.

The rear deraileur seems to be having some trouble shifting up towards the bigger cogs starting at 11, I had to give it a nudge by pushing the cage before it will jump to the next gear. Once it gets past 23 or so, it will continue on its own all the way to the top (52) and have no issue downshift back to 11. The same problem repeats again when it tries to start out the gate to get from 11 to the next bigger cog 13, needed that nudge, same thing with going from 13 to 15, and from 15 to 19, the shifting issue goes away once it reaches 23, it could go up and down between 23, 26, 30, 34, 40. 46. 52 with no issue. At first I thought it was the battery, then I make sure it's charged fully, same problem persists.

Admittedly, the Di2 bits were acquired recently, used and scratched up, maybe a bit longer in the tooth. Is it possible that this old lady is in its last leg....hope not, I was impressed that it could handle the 11-52 cassette to be honest.

[Spdntrxi]

I only managed a 46t with that setup.. 52 seems a bit much.

[weisan]

I took the wheel off and ran the shifting through the steps, bit of finger pressure stopped it at its tracks and prevented it from shifting up.

Confirmed just a weak, worn out motor.