My new alumicross has an internally routed brake cable, or i guess I should say it has an internally routed brake cable housing since it's sized to shove three feet of cable housing through. I'd like to figure out a way to make it just the cable going through the frame. An end button for aero levers won't fit through the front hole and, being rounded, kind of seats in there OK, but the rear hole is a bit bigger. i have a couple of things that look like this:

http://www.loosescrews.com/index.cgi...d=992255716237

And I was thinking I could kind of shave the edges so it seats in the hole better, but... I'm just not sure about the whole deal. Anyone ever do this before? what I need are some plastic plugs or something, but I'm not aware of any sort of product like that. Opinions?