SRAM Rival eTap Rear Derailleur Cannot Shift All The Way Inboard

Question

I have set up a number of eTAP SRAM rear Derailleurs and never had an issue. I set up a 44 tooth XPLR cassette with the XPLR Rival eTAP rear Derailleur. I got the chain sized, on the pulleys and everything looked fine. For doing the micro-adjustment it was difficult to do it with the chain on (you have to align the pulley with the 2nd to largest COG). The alignment never worked right and I found that I could shift all the way to the largest COG and all the way down to the smallest - but the shifting would stop half way up the COGs and never got to the top.

I could see the shifts signaled to the Derailleur by the flashing of the indicator light when I hit the shifters up or down.

Every now and then the shift would go all the way to the largest COG but this is only after I seriously mess with the mirco-adjustment whereby it moves a whole shift up or down.

The Derailleur is brand new and the issue started right at the install - didn't put any miles on the bike.

Any ideas?

Answer 1

Turned out that I had mis-counted the number of links that were supposed to be in the chain. There one extra link and just that one link (or link pair) created the issue.

It threw off the chain gap (even when set up as measured with the XPLR chain gap tool). The tension was off - even though there was no way to see or tell this.

Removed the chain links that were excess and the shifting was perfect. The shift adjustments had to be done again but everything was dialed in.