On Sun, 11 Aug 2019 19:09:21 -0700 (PDT),
Chalo wrote:
Note that Shimano road and MTB 10 speed derailleurs have
different pull ratios. Rear derailleurs and shifters are
miscible up to 9 speed.

This might be why I could never get really good shifting on my
tandem, which came with 10-speed Shimano brifters and mountain
bike (XTR?) rear derailer. I could adjust it to shift well across
only part of the cassette. I swapped the rear der for the newish
long throw road derailer, and it now shifts beautifully.

--
Ted Heise West Lafayette, IN, USA