On Tuesday, October 27, 2020 at 12:46:21 PM UTC-7, Tom Kunich wrote:
On Tuesday, October 27, 2020 at 11:48:13 AM UTC-7, AMuzi wrote:
On 10/27/2020 11:02 AM, 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.

You symptom means there's an improperly set rivet or a
snaplink not completely locked or an actual damaged link.
This is a rider safety issue so backpedal in high gear to
locate the offending link, examine closely and either
correct that problem or replace the chain.

If you have any doubt, replace the chain as a broken link
especially while standing in traffic can mean a serious injury.
Inspected, nothing can be seen and the skipping ended with the ultrasonic cleaning. But the chain is worn out with the chain measuring tool so it will be replaced. I don't stand to accelerate away from a stop light or sign so broken chains are usually nothing more than a nasty surprise. What is even worse is a broken pedal axle or in one case the retaining mechanism that holds the pedal on the axle broke shooting my foot out to the side and making me lose my balance and fall directly in front of traffic. Fortunately, I had accelerated away from that sign so rapidly that I was well ahead of the cars and they had plenty of time to stop.
As I was noting that there were two 10 speed rear Campy derailleurs on eBay with different configurations of the idler pully frame it struck me that the only difference was that they were put together upside down. Took the second one I had and reversed it and it is fine. This is something that you can't do with DuraAce. It only goes together one way.