Originally Posted by
HillRider
Why? This makes no sense as you will want to know when the chains are worn anyway. Even if you more than one they won't last forever.
There are three possible outcomes.
1. You used too few chains. The chain wear rate exceeds the cassette wear rate and prematurely wears the cassette. Start again when when the cassette stops functioning to your satisfaction.
2. You used the right number of chains. The chain wear rate matches the cassette wear rate. Start again when the cassette stops functioning to your satisfaction.
3. You used too many chains. The chain wear rate is lower than the cassette wear rate. Start again when the cassette stops functioning to your satisfaction.
In all three outcomes cassette wear determines the point of chain replacement which is why you don't need to know how worn the chains are.