Need to replace Shimano FD-M191 I need to replace a rusted up Shimano FD-M191 front derailleur.  This is the original equipment on my 2010 Fuji Absolute 3.0, which has 3 gears in front and 8 in back.  Acera SL-M310 rapid fire shifters. Seems like FD-M590 for FD-M360 might work?  So many models.
There are a number of criteria when selecting a front derailleur. The number of gears must match. You need an 8 speed triple with a clamp diameter to match your frame. This is assuming that your derailleur clamps to the seat post. This is where things can get complicated. Some clamps come with an adapter to fit more than one size seat post. The next option is a high or low mount clamp. This is determined by the location of the clamp in relation to the actual part that does the derailing. Another criteria is top pull or bottom cable pull. This is another area where they make units that will work either way depending on how the cable is routed. I have access to an 24 speed Absolute DX. It has a 31.8mm/high mount clamp and uses a bottom pull design.