Ritchey Cable Tension Barrel Adjusters

I recommend this product

I didn't do what it said on the pack. I've shoved one of these into the end of my XT rear derailler to provide inline adjustment for my 9 speed barcons. Even under tension, the bit that is supposed to turn, turns, and the bit that isn't supposed to turn, doesn't turn.

There is a little lateral stress due to the curve of the last section of cable outer. Will see how it holds up. If not, I have a spare that I can use in the cable boss on the downtube.

I recommend this product

These are great. One thing that makes them so is that they work well under tension. No matter what position the mech, they turn really easily. No noticable slack is created in the cable run.

I recommend this product

I run an old MTB frame as a CX style trail and road bike with MTB gears and these fit neatly into where the cables come out of the STI's to give me accurate indexing neat looking product and works well.
Though I would guess won't work with the latest STI's that route the cable out the back and under the handlebar