Thanks guy153 and Andrew R Stewart . Good point about leaving some room on the inside diameter of the guide. That is one of my concerns with brake line (pipe) . The 3/16" brake line is .188" inside diameter and the derailleur cable housing is .167" . That might not leave enough room for paint and wiggle room installing the cable housing. And if I change the cable housing in the future, it may be a little or a lot bigger.

I make this sample guide from solid copper wire and while it might work, It looks like it would be more difficult than a tube to silver solder on. And I don't really like the look that much.


I might try an art and hobby store and see if they have stainless steel tube. That seems like it would be prefect if they have it. I have mostly seen brass, but perhaps I wasn't looking for stainless in the past so I didn't see it.