The CU chainrings have a different tooth profile from the regular 1/8 chainrings from say, Sugino or Shimano.
The tooth profile is not chamfered, but rather is square. This is a ‘good’ thing in that it’s possibly more durable (although I’m not sure if I believe this).
On the downside this square profile might cause a few compatibility problems with chains like you mention.
I use a Izumi nickel-coated 1/8 chain and it was noisy to begin with, but it’s pretty good now.
+1 for the KMC Kool.
The chunky angluar shaped links i gather are some sort of bmx thing, but out of the three chains i’ve been swapping between lately it’s by far the quietest. It does seem maybe a fraction wider than usual too which might help you out.
Thanks everyone for your replies, I thought it was just me that might be having
this problem… I will be getting a new KMC Z510 chain today.
Thanks again for the advise.