I have Shimano chains, HG 93 and HG 72 (or something close to that) and both have frozen links. They're on road bikes used for commuting, I keep them lubed and soak them in homebrew off the bike every few months, but both have a few links that no longer flex much, causing the chain to skip as it goes through the rear derailleur/cassette. The bikes do at times hang from the garage ceiling for a few weeks at a time without being used, when I'm riding another bike, and I live in humid Va Beach, but it doesn't seem like they should freeze like they do. Any ideas as to what's happening here?