Shimano GRX RX 815 Series Dealer's Manual page 72

INSTALLATION/REMOVAL
Installing the rear derailleur
2.
Secure the rear derailleur.
Be careful not to insert the rear derailleur mounting bolt in the derailleur hanger at an
angle.
In addition, be sure to install the rear derailleur so that the stopper plate tab contacts the
B-tension stop, with no gap in between.
Rear derailleur mounting bolt
8 - 10 N·m
B-tension stop
Stopper plate tab
NOTICE
• Periodically check to make sure that there is
no gap between the B-tension stop and the
stopper plate tab. If there is a gap between
these two parts, problems with gear
shifting performance may occur.
Stopper plate tab
72