Originally Posted by
Andrew R Stewart
Shimano has claimed a service recommendation for a cable replacement about every 1000 miles.
That's nuts. On the other hand, I've had a current generation 105 11sp rear shifter shred a cable in about 1000 miles. More typically it takes about 3500 miles.
Note that the OP is in PA, which is where I was living until recently. If his/her terrain is like mine was, there is a LOT of shifting. I broke rear cables so often that I considered switching to downtube shifters. But I moved to the Great Plains instead.