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..

KMC chains elongate over time due to pin an roller wear like every other chain. No chain stretches. They're not rubber bands, and and claiming that KMC chains don't "stretch" is like advertising corn as gluten free. But of course you know that. It sounds like you have a stiff link or your quick-link isn't seated properly. Pretty simple fix. Now that you have removed the chain, you need a new snap link according to the Shimano gods -- or a new pin. So at least one of your potential problems will be solved with reassembly. Another outside possibility is bad tension pulley or even a bad chainring holding on to the lower chord of the chain. That's unlikely, though. You should test ride your bikes before you try to sell them -- and how come you keep buying bikes, throw money at them and then sell them? You have to be taking losses. It's "buy low, sell high" -- not the opposite. The market for a used XL rim-brake Madone has to be tiny.


-- Jay Beattie.