
Installing a new chain - length and direction
Sizing and installing a new chain for your Di2 bike isn't hard, you just need to follow the right steps. This page quickly shows the chain sizing methods and explains chain directionality.

Part of the 2x12-speed GRX groupsets, this FC-RX820-2 gravel crankset is the crankset to use with RX825 Di2.
It has a chain line of 47mm, P.C.D. of 110/80 and the Q-factor is 151mm.
The crankset is available in 170mm, 172.5mm and 175mm crank arm lengths, and comes with 48-31T chain rings.

Sizing and installing a new chain for your Di2 bike isn't hard, you just need to follow the right steps. This page quickly shows the chain sizing methods and explains chain directionality.