The best way is to service it regularly. This mostly involves removing the internals and bathing them in the specific Shimano oil bath. In London I’d say do this at least yearly.
The real issue is with the main bearing on the drive side. The bearing race is built into the ring body and isn’t replaceable, and it this which seems to wear out and gets pitted. It’ll still work but it’ll sound like shite.
The best way is to service it regularly. This mostly involves removing the internals and bathing them in the specific Shimano oil bath. In London I’d say do this at least yearly.
The real issue is with the main bearing on the drive side. The bearing race is built into the ring body and isn’t replaceable, and it this which seems to wear out and gets pitted. It’ll still work but it’ll sound like shite.