Sweetcheeks: Seat cover for monkey butt prevention.
See this thread
Ray's web site seems to be down, but he was still selling them as of a couple of months ago. PM him for info?
I originally purchased them just for the paved ride down to TN. However, they didn't interfere at all while riding, (unless standing up while really steeply descending), and ass comfort was um... intolerable after about 30 minutes without it on the stock seat.
LDF rode the first day without them. Tried them the next day, and used them the rest of the trip. They look a little weird. Don't care.
I was a bit concerned that they would wear out over a long ride, but the canvas just sort of fades, like blue jeans. No holes after 3400 miles on mine.
There was one stretch in NM after we left the TAT where we had 200 miles (we had a 206 mile range) to a "maybe" gas station. The next nearest "for sure" gas stop was 28 miles further. I filled two 2L bottles as reserve. Obviously NOT a recommended nor long-term solution for storing gasoline, but it worked great for the few hours we were on that one section.