Mine frays and needs replacement quite frequently (every 4K miles or so). A friend of mine has had the same thing happen. Should this just be considered a maintenance ritual with 7800? I'm beginning to think so. How is it on 7900?

Sounds to me as if there is something wrong with it.

I use Campy 11 and have gone through 2 right shift cables in 16,000 km. I think that's not good enough and there may be something wrong with my setup.

I wonder if Powercordz or other after market cable may be more durable.

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r o y g b i v

Okay, sorry.. typo. It's the rear shift cable, right side.
I guess 2 in 16000 Km isn't much different than what I'm getting. It does seem to be a pain though, because there is no really easy way to tell when they are going out other than "poopy shifting".
I do my miles on three different bikes and it I am too stupid to keep track of how many miles are on each, so I end up getting surprised on my rides.

I have 4 sets of 7800 and ride over 4000 miles a year and have had no such issues. Some of my rear cables probably have over 8000 miles on them. I built all the bikes myself and am very meticulous. Is it possible that you have done something wrong? This groupset has been out for 6 or so years and this is not a known problem.

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For certain parts stiffer is more important than lighter.

Disagree. It is a known problem. From both 6600 and 7800. On some shifters there is a rough edge eight where the cable head beds in. Over time, about 6 months of 12 hrs a week, the cable will fray and pop. Warning is typically needing to dial out the barrel adjuster every couple rides for a little bit, then it goes. There are even threads online about how to drill an acres hole to get at the orphan heads if it gets jammed up.

Anecdotely, almost every 6600 and many 7800 users ice talked with have this experience. It's considered regular maintenance. Worth it for the perfection of 6600/7800 shifting action.

I tried finding the official line on Shimano's site to no avail. However Campagnolo do have such a document on theirs.
http://www.campagnolo.com/repository/do ... onents.pdf
They suggest every 20000km or two years for full cable replacement, unless you're racing, Then its every 15000km or annually.

I replace my right shift cable religiously every 2000 miles on both my 7800 and 7900 bikes. If I don't, it frays and starts breaking, and it's a total pain to remove at that point. I've broken lots of them and when I remove them at 2000 there's usually initial signs of fraying (and sometimes some broken strands). I'm sure there's something I do while riding to aggrevate the situation, but that's the way it is.

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CLB

Do you lube the cables when installing them? That may be your issue.

I had the head pop off a front derailleur cable on 6600 a few years back (not sure on use but I'd guess 6-8,000 miles). As mentioned below I'd spent the ride playing with barrel adjusters then 'click', found out why.

I started swapping cables annually as part of post winter maintenance.

I don't think I'm doing anything wrong, and I do lube the cables. It seems like a pretty straight forward operation, and I've put together and maintained a lot of bikes over the years. But I'd be thrilled if someone could point out a trick that would prevent this. Sounds like it's gotta just be part of my maintenance schedule. BTW, once this happens they are a pain to remove, but the trick is to push the head of the cable out of the shifter just enough so that you can get get some cable snips around it and cut it off, then pull the cable out the exit side.

That's normal cable life for 7800 shifters. 4000 miles in the most I'd go with cables on those shifters before they start fraying.

It seems like cable life would depend on how often you shift.

I shift a lot. More than the people I ride with. 3k miles seems to be typical rear shift cable life for me.

The problem is the small diameter of the pulley that the cable wraps over. I don't see how any change in installation could make it better, but if someone has a trick I'd like to hear it.

I do know a trick for inspecting the cables- shift to the large cog and pull the brake lever. You can shine a bright light into the cable insertion hole and peer through the hole at the cable to see if there are broken strands.

Usually I can tell that the cable is starting to break because shifting becomes less reliable. I have yet to have a rear shift cable completely break, but I did have the front break on my rain bike. If I'd been paying better attention I'd have noticed the degradation in shift quality and inspected the cable.

I ran 7800 for years with no issues, must have been lucky

Another thought is that cables come in various quality levels. The Shimano 10 speed ones and some other brands have very fine tightly wrapped wires. You can see the difference between those and the $2 ones from feet away and also feel the difference in the smootheness if you run your fingers along them. I only use either the Shimano ones or the Jagwire high end ones.

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For certain parts stiffer is more important than lighter.

Hi yourdaguy, are the shimano and Jagwire ones you use teflon filled/coated to keep the fine wire strands bunched together?