I can also see the logic in this and figure that this WOULD actually be more economical.

As I have always understood it.

- Putting a new chain on an old(er) casette wears both the chain and the cassette faster than new/new.
- Putting on a new cassette without a new chain does the same.

Assuming that a cassette lasts three times as long as a chain (which I think is a fair assumption). Rotating the chains at the same frequency you would do a full clean/relube (monthly for me) would mean that overall the cassette and each of the chains would longer.

I admit that you maybe talking about a saving of ITRO 20$ a year for your average setup but I still think the poster has a valid point, in principle.

If I ever fully change to SRAM chains with the powerlink I might give it a go.