Originally Posted by
sw20
No. You really have to try hard to wear out a cassette and chain till they cause a big problem. And you are keeping an eye on it so you will know when it's going bad.
You could order one and have it ready if needed or just the cog you use the most
I have a cassette with with thousands and thousands of miles and I changed the 17 and 19 a few times. And no problems. I keep an eye on it.