I'm not all that familiar with STI. This is my first bike with STI shifters. I have Shimano RSX 3x7 Speed shifters controlling a 7 speed RSX rear dérailleur on a 7 speed cassette. The issue I am having is when I shift from the second smallest to the smallest cog or the third smallest to the second smallest cog or the fourth smallest to the third smallest cog it doesn't always shift. I push in the inner control lever on the shifter but it doesn't click. It is like pushing air. If I push it a few times, sometimes it will shift. If I try and pull the lever toward me and then in, it will shift most of the time. It doesn't always do this but it happens often. Once in a while it will shift with out me having to fidget with it at all. It never happens *knocks on wood* when shifting from a small cog to a larger one.
Does anyone have suggestions on what I can adjust? I'm guessing it is not with the rear dérailleur.