Originally Posted by
jolly_codger
Keep in mind that cables fail due to physical conditions, i.e. the tight bending radii that every manufacturer's brifters inherently have.
+1 this. The experimental aircraft homebuilders have a rule-of-thumb: for cable direction changes, control cables should use a pulley with a radius 50x the diameter of the cable to reduce the likelihood of metal fatigue failure in use. That's not going to fit inside any brifter. And yes, downtube shifter are also subject to this issue, but there at least impending failure is far more obvious than with a cable hidden inside a brifter.