Noisy drive train

Hi
I recently replaced a broken wheel and given the age of the bike, bought a new cassette and chain.
It's an 8 speed sunrace freewheel with an 8 speed kmc chain. Prior to that it was an 8 speed shimano cassette.
Fitted it all OK, adjusted length of chain accordingly and it works fine.
It's just very very noisy. Previously my set up was silent. Now you can hear the chain running through the system of gears and jockey wheels.
It's been lubricated well too. I just wondered why these components make so much noise or if there is something I can do to aler this.
I recently replaced a broken wheel and given the age of the bike, bought a new cassette and chain.
It's an 8 speed sunrace freewheel with an 8 speed kmc chain. Prior to that it was an 8 speed shimano cassette.
Fitted it all OK, adjusted length of chain accordingly and it works fine.
It's just very very noisy. Previously my set up was silent. Now you can hear the chain running through the system of gears and jockey wheels.
It's been lubricated well too. I just wondered why these components make so much noise or if there is something I can do to aler this.
0
Posts
My first thought. easy to thread the chain over the rear mech tab instead of going under.
Failing that, it may all quieten down a bit after a few hundred miles as the new components get to know each other
PP