Out for the Saturday afternoon ride when I notice that my RD shifter is giving some resistance when I shift; it feels like the cable is binding somewhere. Re-tuning the RD after the ride and visually inspecting the cable, I don't see anything wrong but the shifting is getting worse. Pulling the hood away from the shifter reveals frayed cable coming out of the back of it (sorry no camera). After some frustration I manage to extract the damaged cable from the shifter (the ratchet needs to be zeroed to get the cable out), but I can't figure out how this happened. The cable is three years old, so there's that, but I'm surprised that the cable failed where it did. I can't take the shifter apart or I void the warranty, but I was curious: has anyone else experienced this? Did you find the cause of fraying?

Thanks!

Gear cables fray from metal fatigue. The drum on levers has a relatively small diameter, and as the cable winds on and off while shifting the repeated bending eventually gets to it, leading to fraying and breaking.

I can't give you a life expectancy in miles or years because it isn't related to time and distance. It's a function of how often you shift. Folks riding the roller coaster terrain of places like Connecticut will have shorter cable life than those in the plains or even in the mountains of Colorado, who can ride many miles without shifting.

There are lots of posts on extracting the broken end of the cable from DA levers, so do a search and see if you find somehing that works for you.

For future reference, cables usually give you a bit of warning before failing completely. The lever action becomes stiffer (as it did for you) a short while before the cables let go. When you feel the change, finish your ride and replace the wire at your first opportunity, before it becomes harder to remove.

Makes sense. I did manage to get it out, but now I know for the future. Thanks again!

Many an STI lever has been butchered for this.

Another potential trap for noobs is failing to ensure the shifter is fully released before threading in a new cable (easy enough to bump the lever while the cable's out), and missing the hitch on the drum... had a bugger of a time a couple of weeks ago sorting that for someone.