Anyone had this when setting up a rear mech?

When in the smallest sprocket the cables tight and changes up OK,once in the largest sprocket it’s taking 2 or 3 shifts to get the chain to start moving back down.

On closer inspection the slacks being taken up by the outer flexing and bending due to the inner becoming tight, have I cut the outer too short?

Any tips before I pop it into the LBS in the morning, in 15 years I’ve never had this problem before.

Yes, the outer may be too short. I usually cut it about a cm longer than required, over time it will bed in to the correct length.

Prob. Pics?

Not set up with a camera at the mo, I’ll experiment with some longer outer in the morning.

Just checked, I cut the outer so that the bars rotate the full 180
the cables tight against the headtube at full lock at 180.

Does that relate to the problem?

Yeah, its the section from the shifter to the frame that’s causing the problem.