Shimano GRX RX 815 Series Dealer's Manual page 98

INSTALLATION/REMOVAL
Securing the front derailleur
3.
Readjust the position of the chain guide.
Adjust the support bolt so that the flat portion of the chain guide outer plate is aligned
with the surface of the largest chainring. Make sure that the support bolt is in contact
with the backup plate.
Support bolt
With mounting boss Without mounting boss
(direct mount) (use band adapter)
TECH TIPS
• Check the adjustment position by pressing a hexagon wrench or other tool to
the flat portion of the largest chainring.
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