Originally Posted by Joe Remi

Here's a couple pics of my Nexus 7, it looks the same as the Nexus 8 (sorry the background makes it kinda hard to see). The cable attachment point is inboard of the stay, you might be able to find a vintage metal clamp-on cable stop to mount halfway between the hub and BB shell. Then you'll use one groove under the shell (if it has them) to run the inner wire up to another stop on the downtube. This is for chainstay mounting, I don't know enough about vintage frames to figure out how you would use seatstay/toptube.