Nope..for Campy in particular and also for Sram and Shimano, routing derailleur cables behind the bars typically manifests the best shifting with less internal cable drag. I even opt to routing my derailleur cables outside and around the back of the FSA Kwing carbon bar versus internally which it has provision for. I run the brake housing thru the Kwing...but derailleur cables around the back. Bottom line is the back edge radius is less tight then the front radii of a handlebar...difference in radii being equal to the width of the handlebar.