Ste_S

I bought a new in-line barrel adjuster as my old one seemed to be corroded.

I've installed it along with some new cable, and turning the barrel (either way) doesn't seem to be doing anything. I initially tried it on the middle ring of a triple, and then on the inner ring and with no change.

What am I doing wrong ?

cascade168

My experience with in-line barrel adjusters is that they are - at best - not very good. FD cables have a LOT of tension on them and even barrel adjusters that are anchored on down tube bosses are tough to adjust.

OK, so let's make the best of what you've got ...

First, it's almost imperative that the barrel shifter be dismantled and the internal threads greased. This will help a lot. Next, the barrel shifter should be set for minimum tension (i.e. screwed together) when you do your initial cable tensioning during the FD alignment proceedure. By this, I mean that you should be on the small chainring, have the "L" limit set properly, have the FD height and rotation set properly, and then pull the cable tight and lock down the cable locking bolt. With all of that set up properly, you can shift to the middle (on a triple) or large (on a double) chainring and adjust your cable tension using your in-line barrel adjusters. You need to crank out the adjuster until you see the FD cage move. Again, because of the considerable tension on that cable, this is not easy. You might put four or five turns on the adjuster before you see the cage move. The higher the initial tension on the cable (as described above), the better the adjuster is going to perform.

If you need help with FD adjustments, go here:

https://www.parktool.com/repair/readhowto.asp?id=75

Plan on using two hands to use these adjusters. If you can get them to work with one hand, you are one very talented person. What this implies is that you can pretty much forget about doing cable tension adjustments while you are riding. The good news is that once you have your FD cable tension properly adjusted it only rarely needs a small tweek.

The moral of this story - at least for me - is that one thing that should be of prime consideration when buying a bike is to look for down tube bosses for barrel adjusters. They are far superior. The next best solution is cable adjusters that are integral to the brake lever housing. These are usually found on MTB types and cheaper road bikes. It really amazes me, though, that a lot of $1000 road bikes have these crappy in-line barrel adjusters. I would never buy a bike with them. Sorry about the editorial, but that's the truth of the matter.

DannoXYZ 

What kind of results are you trying to achieve? A cable-adjuster on the FD will only change the position of the lever where the chain switches between chainrings, but it won't do a thing for how it shifts. Also, what kind of shift-levers are you using? Front-derailleur indexing is sensitive to chainring spacing and your crank should match the spacing expected by the levers+FD combo.