If you look at the cable fixing screw, it's attached to a cam plate that has a half round cable guide milled in the edge of it. The cable comes up from the bottom, wraps over and around the cam plate cable guide and attaches to the bolt. When using with a top pull, the cable just comes straight down and attaches to the bolt.
edit: Shimano has three different XT front derailleurs, the FD-760, FD-760-E and FD-761. The 760 and 761 have different style bolt fixing plates but the idea is the same. For bottom pull, the cable wraps around the plate to reach the fixing bolt.
Last edited by Proximo; 01-28-07 at 06:02 PM.