Originally Posted by legalize_it
heres a little picture i made in paintbrush of what i always thought chainsuck was......in my pic you can see what i meant in my previous post by the chain continuing to wrap around the ring
You are right legal, that is chain suck. His trouble is the chain slipping off his low ring. Caused by too much slack in the der cable or low der limit screw out of adjustment. Both easy fixes - tighten the cable (most likely) or raise the low limit der screw.