Originally Posted by
Jipe
Shimano RD-R8000-SS short cage is limited to 30t for the cassette, it doesn't accept a 32t or 34t biggest cog while RD-R8000-GS goes up to 34t.
As said, a Shimano 53-39 crankset is a road crankset with a narrower chainline than the Birdy original crankset and might not work with a front derailleur (same as
the Dura-Ace 7800 of 50PlusCycling which doesn't work with a front derailleur). So, again, I advise to at least first try to mount a BCD130 53-39 on the original crankset.
Do you mean FD will not work because Shimano crankset with double chainring will be too close to the frame? Can’t the crankset be moved out with spacers to widen the chain line for FD to be used? I assume it should work somehow as there are factory equipped Birdys with front derailleurs.
Regarding 53/39 BCD130 do you think
this chainrings set can be mounted on stock spider and allow using front derailleur?