For the past couple days I have noticed that my FD has had a little bit of a tough time shifting on to the big ring. IE, I would need to put more pressure on the brifter in order for it to move far enough over to solidly get my chain on my big ring. Well today, My FD got completely messed up. It is kind of hard to explain, but I will try my best. Basically, when on the smallest ring (its a triple) everything is absolutely fine. However, when I move the brifter so that it should shift onto the middle ring, it does but the chain rubs the FD, and it sounds like I'm cross chaining really bad. Then, if I shift the brifter so that normally it would put the chain on the big ring, it just moves the FD enough to eliminate the rubbing, but stays on the middle ring. This basically leaves me with a double, as I have no use of the biggest ring. No one has touched anything on the bike with a wrench, but the past two days of riding have been in the rain. I have cleaned my chain in a few weeks, but I doubt it would cause this.

Basically, I know that I need to make some adjustment on the FD, but being a novice bike mechanic, I don't know what to do, but I would like to learn. Any help would be appreciated. I know I could bring it to my LBS, but thats a 1/2 hour drive which means at least one missed day of riding, and possible more if they need to keep it to look at it another day.

The crank is a FSA Omega MegaExo with 30/39/50T chainrings. The brifters and FD are tiagara parts and the RD is 105. Thanks for any help