Chorus eating cables
 

Hi everyone,

So this story began when my campag centaur shifters had to be replaced thanks to a tiny plastic part wearing out that couldn't be sourced anywhere. Not happy but got over it. I've had the new Chorus shifters for three months now, and have just noticed the cable for the rear derailleur is frayed inside the shifter. I ride about 250km/week on undulating terrain so do shift a lot - but three months, this is crazy.

The cable is chewed about an inch down. I suspect this is where it exits from being in contact with the cylinder of the shifting mechanism (if you can imagine what I mean). There is plenty of grease so I don't know why this would happen. Does anyone have any clues? Or is this yet another design flaw I need to live with? One thing - I do use these shifters with a Centaur derailleur, but spoke to a few guys before who assured me they would be compatible. I've had 10x more life out of the sora groupset on my winter commuter :-(

Any help would be very welcome - thanks!

Cables typically fray and break inside the shifters because of metal fatigue. The cable is wound on a drum, and winds and unwinds in a small area as you shift. This constant back and forth work hardens then breaks the strands one by one until the cable fails.

The process is similar to bending a paper back and forth until it gets brittle and fails.

A contributing factor is aggressive, this applies added tension during the bending and speeds up the fatigue rate, but this counts far less than the unavoidable bending itself.

I suspect that your problem is simple fatigue, and not related to the levers as much as the cable. Possibly the new wire was of a different alloy or condition and more prone to work hardening. Also note that the die-drawn (smooth surface) wires used on modern shifters are far more prone to the problem because they're not nearly as supple as the wires they replaced.

My advice would be to try a different brand of inner wire (make sure it has the right head) and see if that works out better.

BTW- if it makes you feel better -- back when I was Campy's east coast service tech I found that riders in Connecticut and Pennsylvania had the shortest service life out of both their G-springs and cables. I chalked it up to the constantly changing terrain which made for frequent shifting.

Good quality galvanized steel would very likely out last stainless. Good luck finding such for Campy.

Could there be something accidentally scraping against the cable ??

Do these Ego levers have two casing routing options? One along the front of the bar and one behind the bar? Is one route a greater corner for the cable to deal with? Andy.

They should.

Optimal routing produces a less aggressive bend depending on where and what shape bar you are using. This will be obvious when you are replacing/installing housing from shifters

That's very normal for Ultrashift levers (Chorus and above 11 speed, 2009-2010 Veloce and above) where the tight 90 degree guide causes fatigue failures. I get 2500 miles out of OEM Campagnolo rear derailleur cables.

2637 miles:
http://bikeforums.net/attachment.php...hmentid=448866

New Shimano levers with under-tape routing have poor life for the same reason.

With pointy hood ergo levers the housing approaches nearly vertically and I got 4500 miles with fatigue failures nearer the head from wrapping around the shift drum.

1998-2008 rounded hood levers are also made like that but offer bar front and rear approaches for the housing.