Bicycle Chains

KMC on Shimano drivetrain offer much better shifting than Shimano chains. EL, SL and above are comparable quality. I fit hundreds a year and never have issues. Mechanical Ultegra is noisy on any chain in the top two gears. 

I've never had or heard of any issues with KMC chains before, although I haven't used them recently. I've quite often read that KMC make many of Shimano's chains - although I don't know which ones (or even if it's actually true). Anyone know more ?

Have you checked the wear on the cassette & chainrings? These will wear to fit the worn chain, and then putting on a new chain will be noisy.

Also, factory grease is there to stop it going rusty on the shelf, not to lubricate it.

I've never experienced a duff chain which was noticeably different from all the others. On the other hand, I haven't gone above 9-speed and I assume 13-speed have chocolate side-plates

Can't say that I've noticed any issues with KMC chains

Did you clean the new chain to remove factory grease? Apparently it's not always the best lubricant, maybe the noise will get lower with time and a better lube?

New chains often feel different, but after a while I don't notice much difference, I had KMC, Shimano and now Wippermann on 7 speed...

I just replaced my 11 speed with a new Shimano 105, it was also notably noisier than the old (~same model), despite using Flowerpower this time, which is supposed to be LESS noisy than Squirt. I was also disappointed to see that the previous chain was over 0.5% after only 4000 km despite a lot of attention (it was the first chain I have checked, degreased, drip waxed carefully, before that one I used to only add some light oil when they were too noisy, cleaning was done with a paper towel or old cloth...)

On ZFC both KMC 11 & 12 speed have excellent performance ratings... but Sram 12 speed XX1 and X01 have the best longevity (at twice the price of Simano 105 though so not worth it financially).

That said I'm taking ZFC's results with a grain of salt, drive trains are already relatively complex systems, with different gears, usage and evironments for every rider....

Depends. On lubricant and type of chain.
12-speed kmc seems to be of lesser quality then the 11-speed ones..
Kmc x-11 el was my go-to cgain for years.
Very good !
Tryed sram but was not impressed.
A chimano xt chain does not convince me seems to rust more (waxed)?
A dura-ace chain performs better, i just bought a ybn chain because of great reviews it gets.
Just to see if it's better ..😁

Was it actually a kmc chain or simply one passed off as kmc?