Originally Posted by
Chris_W
Regarding the cage on the 6700 derailleur: I think the upper pulley position may be slightly different on the GS version than on the SS because it is only the SS that is rated for a 30-tooth cassette, I believe.
Actually my comment (as spaghetti-like as it was) was a comparison of the Di2 6770 SS vs the mechanical 6700A SS (that was shipped in error). Both the SS and GS versions of the 6700A were revised to accommodate a 30T.
Specs of the 6700A GS version:
Max sprocket: 30T
Max front difference: 22T
Total capacity: 40T
Swapping that cage to the Di2 6770 should allow this newer RD to achieve the same specs. Many people report the Shimano specs are conservative and have success using the 6700A with a 32T cassette without any issue (maybe using a lot of the B-tension screw, but that depends on your hanger length - some are longer than others). Further tweaks are to use a 10T upper jockey for a tad more clearance, which I am thinking may get this 6770(A) up to a 34T.