Originally Posted by genejockey

I'm wary of letting derailleur cables get too old after the time I broke a rear cable on a ride in the pre-cell phone days. I was about 8 miles from home, and no pay phones en route, so I ended up using my chain tool to break the chain and re-make the drive train as a single-speed with small ring and mid-cassette cog.

Since then, none of the cables I've replaced has been frayed, so while I'm not getting all the use out of them that I might, I'm also less likely to find myself in an "Aw, crap, the cable broke!" situation.