Originally Posted by
KCT1986
The comment about the front derailleur is wrong! If the front shifter is going to be changed to 11 speed verson, the 10 speed FD will not work properly. The 11 speed FD needs more cable pull to work 'as intended'. With a double front, you could probably get it to work, but will not be ideal, the trim positions may pose issues.
The FD-4700 is 10 speed but uses the 11 speed cable pull, both front and rear.
So in that case just add the ST-6700 for the front DR that he already has on the willier that's being cannibalized. More savings if the OP can get past the idea of the left and right shifter having different names on them.
I've got an 105 5800 spider with Ultegra 8000 rings and a left side Ultegra 8000 crank. No one has noticed yet. With the exception of the bike shop mechanic I go to sometimes.