does anyone have any advice on working with cables internally routed on my dual - if I need to remove them for any reason?
I’ve been working with internal cables for many years. The only advise I can give is to re-thread using ONLY new cables. Never try and put a used cable back in. Be patient!!
Cervelo internal cables are some of the best in the bicycle industry. They are very easy to replace. Just do one side at a time, to make sure that the cables do not cross inside. When you use new cables, as Getting-Old said, they will go straight through the downtube and out at the bottom bracket area.
For those who might have a more difficult internal cable routing situation, I’d suggest removing the existing inner wire and skipping in some other wire or high strength fishing line long enough to fit into both the old and new housing. Then you can pull the new housing through the frame using the old housing as a guide. The wire/line “ties” the two sets of housing together. The Trek TT frame is pretty tough to replace the rear brake cable housing on, but this made it a minor task.