Yes

IHOP do you have this set up on your bike? Did you have to do anything with the shimano firmware to make this work?

@IHOP

All 9070 and 6870 pieces are cross-compatable. As with any di2 installation, you may need to update the FW.

Do some searches. I seem to recall reading that you used to be able to do this, but recent firmware updates require that the RD and FD match.

Assuming it is 6870 or 9070 they are all all compatible with each other. Just get the internal battery charger and hook it up to your pc and do a firmware update to ensure they are all up to date.That combo is a good choice as i think the DA 9070 RD is slightly better at shifting under power, smother, and lets be honest looks way better. I cannot tell a difference between the FD's.

Sorry, I missed the Di2 part in your subject line. I initially thought you were just talking mechanical from reading the body of your post.