I'm fitting aero bars and kelly take-offs on an old steel frame, and the fairly stiff compressionless housing for the index shifters I have just won't behave without crossing from left shifter to right cable stop. That's fine. The problem is, I have top-of-bottom-bracket cable guides, so the x-cross under the down-tube isn't going to work.
The shifters seem indexed the same (I counted the clicks), so could I just use the left shifter for the rd and the right for the fd - is this just a question of convention, or is there a detail that's going to get me? The cable stops are the dura ace variety.