Pardon the stupid question:

I've got a PM fork that is meant to work with a 160mm rotor. I also have Shimano post mount brake calipers.

I have a Shimano adapter that should mate a 160mm PM fork to a 180mm rotor. The wheel in question has a 180mm TRP centerlock rotor mounted.

After the first ride, the wear pattern on my rotor shows that the caliper is around 3mm too far outboard of the rotor radially.

My solution, for now, is that I have filed the adapter to fit, such that it brings the caliper inboard radially.

Am I missing something? Are rotors and adapters specific to one another in some way?