Originally Posted by
CACycling
Basically, if you have the FD on the smallest chain ring, you can pull the cable away from the down tube and it will move the FD out which shifts to the larger chain rings. If you release the cable, the FD should move back to the smallest chain ring. If it does not move back, the problem is between the point you pulled on the wire and the FD. If it moves back, the problem is between the point you pulled the wire and the shifter.
It sounds like you did this and the FD did not return back to the small chain ring. If this is the case, it is either a problem with the FD or the cable between the point you pulled on it and the FD. This narrows down the problem a bit.
It goes up and down the FD no problem when the cable is tugged manually, the problem is only when the chain is on the middle chainring. It's kind of hard to explain, but in a sense, when the derailleur is on the middle chainring it can be in two different positions with the same amount of tension on the cable. On one position it will rub the chain but then on the other, it's perfectly spaced.
So it's like, upshift from inner to middle, no problem at all, but when I downshift from upper to middle, I get chain rub on the inner cage unless I push the derailleur in.