Shimano GRX RX 815 Series Dealer's Manual page 95

INSTALLATION/REMOVAL
Securing the front derailleur
NOTICE
• Make sure that the electric wire exposed in the bottom bracket shell passes over
the top of the inner cover of the bottom bracket.
• If using a frame which does not have enough space between the inner wall of
the bottom bracket shell and the inner cover to route the electric wires use an
inner cover which is sold separately.
Installation example to the thread type bottom bracket
Inner cover
Electric wire
95