I am really not familiar with the way this works in reality, but conceptually I get it. Today I shifted into the big ring and as I did it I notice it was shifting with difficulty. Being friction shift I pushed down a bit more and the chain went onto the big ring. When I went to down shift to the small ring the cable just went slack. It did appear the cable slipped. After the ride I looked the FD over and no adjustment moved anything. the limit screws didn't move the cage in or out cannot budge the thing to make the pivots work. It's like it is frozen, but it makes no sense to me. I took the FD off to clean it and inspect it closer, but I don't see where anything is wrong. Can anyone help me on this or kick me in the right direction, thanks.