Well I will be taking them apart so I will try to see if I find anything out of the ordinary. I am not sure what the cable could be binding on? They went together so easily and worked great for two months.

jiangshi's question was my first impression, that you were using brake cable in an STI shifing application. Mainly because 1) I've done that (still worked just fine) and 2) I've not seen those kind of ferrules on STI cables, just the black ones that are fairly tight.

Lacking that, I've got no clue, housing-wise. I've used the exact same Jagwire Road Pro/Racer kit on dozens of bikes, with no issues whatsoever. In fact, the time I used brake housing on 8-sp STI, it was when I went to a bike shop and that's what they gave me. I've seen bike shops do that more than once, actually, more than twice.

I have seen, over and over and over, the shifter cable able to be inserted in the 8-sp STI (especially the 8-sp STI) without the shifter being "zeroed out." Then, the problem you describe is encountered within a ride or two. That is my guess on this. At times, it is very difficult to fix, mainly because the cable does not want to come out. I've ended up cutting off the extra cable, and just monkeying with the STI until I could get the cable end out.

This is common because the STI shifter will shift on you, just by handling it, bumping it, etc. While you're installing cable, you can "zero it out," and then bump it while installing the cable, and end up with the same problem you describe. I've seen it too many times, caused it myself often enough, to predict with 75% certainty that this is the problem. Pull the housing, pull the cable, insert a new cable, and every 30 seconds while inserting new cable, double-check to make sure it's "zeroed out."

Good luck, feel free to PM me. You deserve a bike that works, and I've seen this too many times to figure it's not worth a try.

Looks defective to me, as though parts of the housing "gave way" or such.
The rear cable is ok ??

I pulled it apart. I have cables exposed on both ends of the compressionless cable housing. On one end, farther than the other. The cable still slides through the housing as it should. This is definitely not brake housing. I know my cut was straight, the cables sticking out form an angle.

Maybe I will cut a quarter inch off of each end and see if I can get another 2 months out of them?

Housing doesn't compress that way.

Two possibilities come to mind.

1- that isn't cable housing, but hydraulic line, and therefore lacks compression strength altogether. This is easy enough to confirm by looking at the ends which should have a circle of steel strands cut end on. Anything else, ie a bunch of thin strands, vs roughly 15-20 rigid wire ends, and it's not cable housing.

2- you used the wrong style ferrules, with conical bottoms, and the structural strands are pinching toward center and extruding through.

Just looking at the outside, I lean toward hydraulic line, but that's just based on cosmetics.

I think odds are good that if you re-insert a new FD cable with the shifter zeroe'd out, and use the fairly tight ferrules that came with the kit, you'll be fine.
Did the FD cable come completely out of the shifter OK?

It was definitely Jagwire cable housing. It was new in its package. I did substitute a ferrule going into the STI lever because I did not like the looks of the stock black one exposed. The tip of that replacement Ferrule does look a bit damaged now that I look closely. But I also have cables sticking out of the other side that had the stock ferrule? I will try cutting this one down and installing it with the correct ferrule. If all it was, was my stupid taste causing this, I will smack myself very very hard.

Join the club. Again.

OK, since we KNOW it's index housing, we need to tweak my extruding theory to match the spiral pattern the OP is getting.

The housing either isn't cut square or it's partly extruding through the ferrule, so some strands are loaded and others unloaded. Since the strands spiral, the unbalanced loading causes the corkscrew effect the OP is getting.

The fix involves 2 elements.

1- after cutting, touch up the end with a file or a quick end on touch on a bench grinder. You want a nice square end, not anything cut at an angle.
2- use proper fitting flat bottomed ferrules made for index housing. These have structural bottoms that won't deform or allow partial extruding of the strands. The best index ferrules have brass or steel discs with a upward pointing cone pressed into the bottom. The slight cone forces the strands out away from the hole, ensuring that they cannot extrude through.

Steve- .... park that thing and exercise that gorgeous Paramount of yours in the AM. DT shifters rule the day. Peter the Ranger is up for a ride too. Yah?

Thank you for the help. I cut them down straight and have ensured they are filed down. I had the stock ferrule in my box. I used a new cable and remounted. So far it works. It still pulls on the housing when I shift up to the big ring. I will watch it closely. I hope that it is the fix. I really do like how these cables look. Why it is only this side giving me a problem when I used the same ferrule combo on the drive side? I shift the rear way more than the front.

Thanks, I may have to look for some of those. I thought all ferrules were the same

Their braided cable housing is absolute garbage. I bought some of the silver stuff for my most recent build and had nothing but problems. I got so frustrated I threw it all out and replaced it with good ol' black Clark's.

I am feeling you. my LBS sells black housing for $1 a foot. I am starting to regret the vanity of purchasing an interesting color if the quality is not there.

here is my stance: it should not friggin matter which ferrule you use - if it comes down to such then the margins for error on your housing is way too lean and you are just cutting corners to make a $ at the riders expense. you won't get my business again with that sort of practice.

I think this is worth looking at.

This is an interesting thread. I always figured a ferrule was a ferrule, good to know the differences. Guess I'll have to check my stash.

Took the bike out for a long ride today. Seems fine. Of course it seemed fine for two months when I first put it together. Now I am concerned about what is under the rest of the ferrules and are all of the rest of my cuts perfect? I know I did not file them down. When will the next failure show itself? Will it be catastrophic? Will I lose my brakes coming down a hill? Oh boy!! With all the things that can go wrong on a bike, I added cables that are extremely picky about perfection. I guess I will need to strip it down and start over if I want peace of mind?