Originally Posted by
T-Mar
You can match them up with any front derailleur. The rear lever is a standard SIS lever (except the detents are less pronounced than New Dura-Ace), so you can use them with any SIS rear derailleur, except New Dura-Ace (74xx series), which had a different cable travel. Again, the light action function is only in the front derailleur lever and refers to a supplemental spring which decreases required lever effort when shifting the front derialleur.
I guess what is confusing to me is the Light Action component group that has a rear derailleur with a separate spring loaded anchor point. Both the 105 and "Light Action component group" have shifters that are labeled "Light Action." Do these Light Action shifters all work the same? and if so, where do the Light Action rear derailleurs fit in?