Thanks for the feedback. I've tried just lightly and firmly depressing the brakes to see if that would make a difference or change the hum noise in any way but it hasn't. I also know it is not the tar snakes or other type of road surface since this happens every time I ride now regardless of the surface. Likewise, I suspect it isn't the tire tread either (though possible I guess) because I have had these tires for a few thousand miles and never heard the humming noise until last week. I was in the middle of a 300 mile day trip through northern NH and while cruising down a country road in the mountains at about 50 mph I started noticing the humming for the first time. Since then, I can hear it every time I ride the bike, but it seems only after the bike has warmed up. As I mentioned before, it sounds like it is coming from the right-center or right-rear of the bike. The bike has about 24k miles on it and the wheels are aftermarket, but where installed shortly after the bike was originally purchased. Any other ideas/feedback/suggestions are appreciated. Thanks again.