Last year I ripped off all my components from my 2000 F300 and replaced them all with LX or XT. My bike came with a bottom swing crap Shimano A or whatever front derailleur. I replaced it with a bottom swing LX. The derailleur didn't perform any better than the Shimano A. Then i noticed my brother's 2002 F500 had a top swing LX. His shifting is perfect and there is no rubbing while mine is rough and there is always rubbing. Will a top swing derailleur solve my problem or is it just coincidental?