Derailleur cables and housing rank among the least sexy parts on a bike. Maybe the seat clamp is lower. Maybe. Few think of their cables. And that could be a problem. When your Shimano 7900 Dura-Ace levers seem to move the derailleurs at a glacial pace, it could very well be the derailleur cables and housing are to blame.
Cables and housing deteriorate. The more you ride, the more you shift. Each shift wears microscopically. The cable will eventually eat through the liner. And that isn't taking into account what the elements do to the cable. It might start off a stainless, coated work of art, but as time goes on and moisture gets trapped inside, it can start to corrode. Chances are, you should probably replace them much more frequently than you do. Our personal interval is once a year on the housing, twice a year on the cables.
So, to get your shifting feeling as crisp as new, it's time to invest in new shift cables and housing. Considering that you have to replace handlebar tape with 7900 shifting, it's a good idea to do your brake cables and housing when you replace your tape. The Shimano Dura-Ace 7900 Derailleur Cable and Housing set comes with two 2100mm x 1.2mm cables, one 1700mm x 4mm housing, and the necessary end caps/ferrules and cable end caps. Choose between Black, or Grey to match your frame.