Originally Posted by ivan_yulaev

Recently replaces my rear shifter cable, after 12,000 miles. This was a standard Shimano stainless cable that came with my shifters. I inspect both cables whenever I do a drivetrain cleaning (~750 miles). In my experience they start fraying either at the rear deralleur or at the shifter, rarely in the middle (maybe under the BB, maybe). Catastrophic cable failure is rare in my experience, it's usually gradual fraying.