I've got an issue that I'd like to ask other rider's opinion on. I ride a Lemond Buenos Aries that I love. I also happen to live in SC and sweat like a hog. The perspiration comes off my head and drips onto my top tube, and has compromised the underneath guide for my rear brake cable. Bottom line is rust! What should I do? I'm guessing I need to remove the cable, file/sand down the rust, and then repaint? But it's such a tight area that I'm afraid my touch-up skills with a paintbrush will adversely affect my brake cable movement. Any advice would be appreciated.