hrdknox1

Shimano Dura Ace 10 spd drivechain 11-23 cassette and 53/39 chainring. I can adjust the rear derailleur to shift properly when in the large ring, but then it does not shift properly when in the small chainring. If I adjust it to shift properly when in the small chainring, then it won't shift to the smallest cog when in the large chainring. I mostly am in the large chainring, but it bugs me why the adjustment doesn't work for both chainrings.

trailangel

Derailleur hanger out of alignment
Front DR needs adjusting
Bad chainline

Wilfred Laurier

Most likely a problem of derailleur hanger alignment.

dsaul

Internal cable routing? If the rear cable and front cable cross each other inside the frame, the front cable puts additional tension on the rear cable when the front is in the big ring. You can adjust it to work on either chainring, but it will never work correctly in both rings.

hrdknox1

Yeah, that's gotta be it. I recently changed the front shifter cable and it may have crossed over the rear cable inside the frame. Thanks. I'll report back if that's not it.

ja6610

...any possibility of the b screw needing adjustment or a chain of incorrect length?