I've seen a rider or two buy sheets of moleskin, and create a wrap around their chin strap. It's a much smoother surface, and one guy says it acts like a "comfort padding." I'd probably go that route before loosening the stap any more. In fact, with the right padding, having it a bit tighter might feel more comfortable. One other option... grow a full beard and let the wiskers act as padding... you know, go for the Sheldon Brown look.
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A conclusion is the place where you got tired of thinking. - S. Wright
Favorite rides in the stable: Indy Fab CJ Ti - Colnago MXL - S-Works Roubaix - Habanero Team Issue - Jamis Eclipse carbon/831