I get the butt chafe, and it's no fun. I wear very lightweight, loose fitting, well ventilated running shorts when I hike, so I've done all I can do there.
So what causes the chafe? I don't sweat excessively and I keep my ass pretty clean by trail standards. Goldbond helps some, but I'd rather just learn how to prevent it in the first place. It seems to be exacerbated by high mileage days, but I'm not going to cut the mileage I like to do just to prevent a sore ass.
Anyone who's battled chafe care to way in on anything that helped you?