I have a Devinci Caribou I and I was trying to adjust the front derailleur. I got the top and bottom stops adjusted right, but it seems that it doesn't downshift correctly from the biggest cog to the intermediate cog. From reading on the internet, I've seen recommendations to adjust the barrel adjustment to fine tune the derailer. Only problem is I can't find the barrel adjustment. The shifter cables come right out the side of the brifters, and there's no adjustment there. They go through the frame, and come out near the bottom bracket. On the cable housing there's something that can be turned that seems like it could be a barrel adjuster, but turning it creates no changes in derailleur position. This turnable part of the cable housing is present on both shifter cable. There is functioning barrel adjuster for my rear brakes, but this is quite different then the possible barrel adjustment for the shifter cables (and it actually works). Can anybody help me out finding my barrel adjuster? Here is a picture of the model that I have, although it's hard to see any of the cabling in this picture.
It is the black piece about 2 inches from where it enters the down tube.
That is the barrel adjuster, but in line adjusters can be difficult get started adjusting, as often they come from the factory with the 2 halves of the barrel adjuster turned tightly against each other.
That makes it appear to do nothing, when in fact the reason it is doing nothing is because it is rotating around the cable housing, rather than activating the adjustment.
Try to hold one half still, while rotating the barrel. Once it is broken free it should work normally. If not, then take it back to your LBS, and ask them to do it, as you will likely have to remove it from the bike to get it free.
Looks like there's an adjuster in-line, right before the cable enters the down tube.
You shouldn't need too much adjustment in your FD via barrel adjustments. If your cable is stretched or your not getting clean shifting just readjust your FD, it doesn't take that long and there are a lot of tutorials out there: