I recall asking Gary Page at Turin Bicycle Co-op in Evanston about a bike s
et up this way, back in the early '80s. He said part of the trick was
to use very stiff cable housing. I'm thinking that if you drill a hol
e in the back of the body, you're going to have a very short throw so any c
ompression would compromise your braking action. And if you're going to dri
ll the bars for internal routing [don't] someone suggested removing the pla
stic sheath to allow a smaller hole. So, I'd suggest just using SIS type de
railleur housing. I set up a bike once for a young woman w/ no left hand by
drilling a small 2nd hole in the Campy Ergo power brake cable pivot a
nd through the body. There wasn't much room so i used SIS housing to the re
ar brake. I don't recall if i used a brake cable or derailleur cable. If th
e former i probably had to file down the pear end as it was pretty crowded
in there. Anyway SIS housing and a thinner brake cable should work for your
purposes. Good luck. Billy Ketchum; Chicago, IL; USA.