Thanks for the great advice and ideas so far! I'm starting to get kind of stoked on the backpack idea. I guess I need to try a few shakedown rides, but I think I prefer the idea of a light bike vs. a light back.

This is my current favorite...the http://www.chromebagsstore.com/bags/packs/pawn-rolltop-pack---small.html?c=96.

I'm planning a 10 day trip through Oregon & California, on pavement (40%), fireroads (40%), and double-track (20%), on a cyclocross bike with drop bars. The bike has zero bosses for racks, so I'd need to go the Carousel/Revelate seatpost & bar bags OR wear a backpack. My entire kit fits in a 22 liter bag, and weighs about 8lbs.

With the Carousel/Revelate gear, I'm worried about thigh chafe on the seat post bag, and losing my hand-positions on drop bars with a their handlebar bag set-ups (no designed for drop bars apparently).

The backpack is just about perfect, but it's well...a backpack, on my back...9 hours a day.

Anyone have any experience or opinions to share? Thanks in advance!