Bicycle Mechanics - Brake cable not fitting

I just completed the build of my new Cove Handjob hardtail. The only remaining issue is the rr. brake cable. I'm using Avid mechanicals and the brake cable housing doesn't fit properly in the cable mounts on the top tube (apparently it's for hydraulic brakes only). The diameter of the cable housing and the corresponding frame mount are different. It just slides through allowing the housing to fall out of the brake lever. My lbs suggested using nylon cable ties to clamp the housing to the frame, it seems to work but looks kind of cheesy. Is there a better solution? Maybe like a ferrule or something that I could use to taper down the size of the cable mount or build up the housing.

As a last resort you can always run a full length cable housing.

That's exactly what I had to do (forgot to mention that). Even with the cable housing running the entire length of the cable, the cable would still become loose unless I zip tied it. There's got to be some kind of "conversion fitting" of some kind to go from a hydraulic sized mount to cable.

How about just wrapping some black electrical tape around the housing to make it larger? If the housing is black you would hardly be able tos ee it unless you looked closely.

That's exactly what I had to do (forgot to mention that). Even with the cable housing running the entire length of the cable, the cable would still become loose unless I zip tied it. There's got to be some kind of "conversion fitting" of some kind to go from a hydraulic sized mount to cable.Maybe a tiny washer might simply work.....slightly larger diameter than your cable housing....but small enough to fit snuggly into the cable stop.

George