On Tuesday, October 27, 2020 at 9:02:19 AM UTC-7, Tom Kunich wrote:
A guy came over to look at my Madone that I have for sale. He rode it around but said that it was making too much noise for him. After he had left, I put the bike up on the stand and discovered two problems, the front derailleur cable had slipped a little but more importantly, the Shimano 105 chain had either locked up a roller or had stretched the chain a little. 105 chains have been touted as having the best "bang for the buck" which is why I bought it. But you could see it sticking as it rolled over the rear lower idler pulley and throwing a wave down the chain when peddling fast. Lubricating with Park Teflon lubricant didn't make the slightest difference and manipulating the chain didn't reveal any hard spots in the chain. But of course that doesn't show a stuck roller or a stretched chain.

In any case I ordered a KMC chain. In their advertisement they specifically say that their 11 speed chains don't stretch which gives me the idea that it is common to other brands.

This is the only time I've ever seen anything like this. As it rolled over the idler pulley is made a definite CLUNK and you could watch it doing it on the work stand. I put the chain in the ultrasonic cleaner and it is now spotless but I will try and discover it that is still occurring and if it is I will measure the chain though since it only occurred on one link I wouldn't think you could measure anything.

In any case, KMC not only has always been super reliable with me but is pretty cheap. Or you can get a top of the line chain from them that is great..
Well, after the ultrasonic cleaning, the sticking link disappeared.

But the chain was extremely noisy still so I lubricated it with Rock and Roll which didn't stop the noise so they I measured the chain and it is worn out after only perhaps 500 miles. Hopefully when the KMC arrives tomorrow that will silence the drive train. I will hereafter stay away from Shimano chains. It isn't as if new parts should be so noisy.

Then I have to pull the rear derailleur off of the Look. In the next to largest cog the derailleur idler pulley frame is dragging against the largest cog. It never did that with the other 10 speed rear derailleur so I can always replace it with the original one that went with the set. I replaced it with the original that had a totally different frame on it and the dragging was gone. Looking at a similar 10 speed Chorus on eBay, it has the same sort of large frame on it that gets in the way. Looking at another, it has the cutaway frame. I wonder what this is all about?