My new road bike build is a carbon frame with integrated shifter cable channels. I have noticed that the channel for the rear derailler cable has one area near the bottom of the downtube where the cable is very difficult to thread. A bend or narrow spot? Anyway the right hand shifting( Dura Ace ,used) seems a bit sluggish compared to another bike with identical components.
Just wondering if anyone has had such a problem, is it a possible cause of the shifting issue, and any suggestions on how to open the channel a bit? Thanks