I should have posted this a while ago, when I figured this out, but that clearly didn't happen. Now with lots of time on my hands, why not? I had posted a coupe of times about the shifting problems the Clem was having. Ghost shifting, never wanting to settle down on a cog, very sensitive to the slightest input from the shifter, etc. At first, I blamed myself. The last time I had friction shifted was back when five cogs in the rear were standard. I figured that I just wasn't doing it right. I had tightened the screw on the hex bolt on the stock shifters to prevent them from slipping. This reduced the problem some, but did not eliminate it. For some time, I rode the Clem as a single speed, since when I would finally get the drive train happy, I never wanted to disturb it again. This was, of course, unsatisfactory. And even though I had been told that the rear derailer was not the cause of this problem, I began giving the wonky looking Claris RD the stink eye. Finally, I decided to replace it. Even though it could not be the cause of the problem. I did have what I thought was a sexier looking Deore LX RD in my parts bin. If I was doomed to have a chattering drive train, it would be with a nicer RD. But it was in the process of changing out the RD that the root cause of my problem was revealed. For as I am adjusting the travel of the derailer, and running the chain through, lo and behold I discover there is a frozen link in the chain!
After a few minutes of flexing the chain, the frozen link is freed, and I finish the install. Now, when I go for the test ride, my Clem is blissfully silent! Shifting is a breeze! I can have any gear I want! Now, some of you old hands at bike maintenance are probably saying to yourselves, "Of course, you big dummy! You should have checked that right away!" Probably true, but I never expected this on a new chain. I've only seen this on old, beat, rusty chains. Anyway, I have since apologized to the Claris for wronging it in my heart, but it's still not going back on my Clem. The Deore remains completely better looking.