Road Cycling - outer casing guide?

I'm installing 105 shifters and decided to replace my cables and housing at the same time (my first time doing this).

The shifter manual's directions refer to an outer cable guide that the housing and inner wire go through..what's an outer cable guide? where can i get one?

They usually come with the set of cables and housing. Just little plastic sleeves that slide over the end of the housing.

No...he's referring to what Shimano shows as an "Outer Cable Guide" on their instructions. Is is a plastic serrated housing-housing that runs under the bar tape. It's "purpose" is to smooth over the feeling of the transition from the bar to the cable underneath the bar tape.

1. You don't need them.
2. Very few, if any, actually use them.
3. In 20 years I have only seen them once.
4. You don't need them.

Outer cable guide = electrical tape [to keep the cable/housing in place on the bar before you wrap the bar in the bar tape] :)

thanks guys...mission accomplished :)