I have just swapped the 105 crank on my Trek 520 for an LX crank (44/32/22). The 105 derailler works OK, but I suspect that an LX or XT derailler which is sized for the smaller chainrings would work better. When I checked out deraillers, I saw that Shimano makes LX/XT front deraillers in "top swing" and "bottom swing". What's the difference? Which do I need> Thanks.
OOPS SORRY! FOUND ANSWER IN FORUM AFTER DOING A SEARCH.