I dug into the archives and didn't turn up anything on this: from time to time I hear a sharp clicking, and I am positive it emanates from the rear brake cable ferrule - the first ferrule, closest to the bars, before the cable travels across the top tube towards the seatpost. I can easily reproduce this clicking by steering side to side while the bike is up on a stand. When I place my fingers on the ferrule, the noise vanishes.
I've tried squirting triflow into/around the ferrule, but this hasn't helped. Should I pull everything off and grease the exterior of the ferrule and the area where it meets the frame? Or is this a sign of a larger problem?
Thanks in advance!