Classic & Vintage - Derailleur cables - with or without housing?

This is probably a pretty simple question, but I'm unsure - I want to replace the old derailleur cables my 89 Bianchi Giro (DT shifters) and I'm not sure if I should use cables with or without housing. I know that originally, the cables were just routed under the bottom bracket without housing, presumably with some grease underneath to cut down on friction. Is that still the way I should do things, without housing?

I don't think you'll need housing under the BB, I'd be suprised if it fit, and either way, I've never had trouble with naked cables in the BB.

(Keep 'em greased to avoid ghost shifting.)

Yea, I'm not sure it would fit either. Thanks, I'll give it ago with the bare cables.

I like to cover the cable with a small length of thin inner housing lininig under the BB.

I normally grab a plastic guide from an old mountan bike and slip it between the cable and the BB. Can't say it's needed, but it seems to make shifting easier and eliminates metal to metal. If I can't find the right type of guide, I use a thick strip of soft plastic and file/cut a groove in it for the cablem then doublestick it to the BB.

Ken.

Hello I find it suprising that your Giro does not have aplastic guide on it.

I like to cover the cable with a small length of thin inner housing lininig under the BB.

+1

This is what I do with both my bikes that route under the bb on steel guides. I go into this habit after having my rear shifter seemingly malfunction far from home. It locked up, and refused to pull cable.
Turns out, the cable guide on the bb shell had gotten gooked up with debris, and the cable was stuck. A little liner that extends an inch or two on either side fixed that issue, and it has never happened again.

Just go to the LBS and ask for some. It is dirt cheap.

My Bianchi came with open brazed-on cable guides under the BB, and my 1980 Peugeot came with a slick (so to speak) teflon under-the-BB cable guide. I do use a piece of old school Campagnolo stainless steel housing under the BB of Capo #1, to adapt it for use with a newer front derailleur which lacks a cable housing stop. None of these systems has ever given me any problems whatsoever.