I'm not aware of any. You could always fabricate them yourself with some sheet aluminum and some pop rivets.
If you chains were loose enough to make contact with the tank you must have been able to hear the fender slap on every rotation. In the future make sure you get the chains on tight. When you think they are tight enough...tighten 'em one more link.
I posted a "howto" in the technical articles on my method for installing chains. Give it a read next fall.