Originally Posted by
jonathanf2
Anyone know if the Di2 signals work with different groupsets? For example, if I were to get the 105 Di2 shifters, would I be able to use a GRX Di2 FD? I'm more excited that the 105 Di2 can run 11-36t native. For my gravel rig I was thinking 105 Di2 shifters + GRX Di2 FD + GRX crankset + 105 Di2 RD + 12 speed 11-36t cassette. Would something like that be possible?
I am not sure you can use an a Di2 FD from an 11 speed drivetrain with any 12 speed Di2 system, at least not without software modification. If I understand and remember correctly, the 11 speed Di2 systems are wired and use a junction box, while the 12 speed Di2 systems are wireless and use a chip in the RD instead. Logically, Shimano can program a 12 speed RD to send the appropriate signal to a Di2 FD from an 11 speed drivetrain, although Shimano has every financial incentive
not to do so. I suppose an enterprising aftermarket software engineer could "chip" the system to provide this function (and risk the wrath of Shimano asserting a DMCA violation), if you don't mind the concurrent risk of voiding your warranty.