I'm replacing my shifter cables and adjusting both derailleurs (for tourer bike) for the 1st time (I knew I'd get around to trying it one day


- The shifter cable set I bought has 6 ferrules, and as far as I can see, 2 of these ferrules (plastic) are for the STI shifter ends of the cable outers, while 3 of the others (also plastic) are for where the cable outers enter the down tube barrel adjusters and where the rear cable outer for the rear shifter cable enters the barrel adjuster on the RD. Then there's a metal ferrule which I guessed is for where the rear cable outer rests on the right chain stay. So my question here is: why are 2 of the 5 plastic ferrules differently shaped? These 2 have a ridge along one side of the outside of the cylinder, and the ends of the ferrules where the cable exits had a narrow plastic tube which looked like it was designed simply to be cut off with a utility knife. Are these 2 different because of the shape of the entry hole in the STI shifters, or something? If it's any help, the shifter cable set I bought is the Shimano Road Shift Cable Set (polymer-coated cables with black cable outers).
- How are the barrel adjusters installed? I can't see any mounting screw/bolt for any of them.
- One of my barrel adjusters won't turn, so is there a way to fix this? I've tried pulling on it before turning, but it just won't budge.
- Right now, perhaps because I haven't adjusted the shifters yet, when I use the inner/small levers to shift either the RD or FD down, i.e. to release tension, I get some resistance, and the shifter makes a loud clicking noise. Is there any way to reduce this? It certainly wasn't this obvious before I replaced the shifter cables. Is it simply due to not having the cable tension high enough? As I mentioned, I haven't yet done the RD/FD adjustments, and haven't yet used a cable stretcher to tension either cable.
Thanks all in advance for any knowledge you can provide to cure my ignorance
