My road bike is outfitted with SRAM Force components. About a month ago, I started to have inconsistent shifts with the front derailleur. Most of the times when I shifted to the big ring, the front derailleur would click back a bit and rub on the chain regardless of the gear I was in on the rear cassette. Occassionally, when I upshifted, the front derailleur would stay where it's supposed to be and not rub the chain.
However today it didn't work at all. When I tried to shift to the big ring, the derailleur would move, but as soon as I stopped pushing the shifter, the derailleur would drop the chain back onto the small ring. I must have tried it 20 times, but it never worked. And it sounds like there's something loose inside of the shifter as I hear some rattling as well.
Has anyone heard of this problem before? Is this something that's user servicable or do you think I have to send it in to SRAM?