Hi
My bike is having 1800miles and I will change the chain for the second time.
I take. Look at the sprocket (15 T on Bosch CX).
I believe the sprocket is fine. Please confirm what I’m seeing.
There looks to be some swelling on the edges of the teeth where the tooth material has been moved. I would prefer to see and feel it myself to be certain. That sprocket owes you nothing, so why not retire it and fit a new one; I'm sure it will run better with your new chain. How is the cassette standing up?