Okay I'll play. Some of you guys have already heard these but here they are again.
1) Hartco Seat w/backrest
2) LD Comfort Shorts - Trust me you won't be sorry
http://www.ldcomfort.com/
Nohandles the bottom line to this question is you need to find what mileage you are comfortable with. There is no right or wrong. I've ridden some high miles & have sat on the bike while I fueled only to ride right away. Other times I've stopped at 150 miles or so & took a break because I wanted to. Last year some of us rode to west PA & down to W.V. looping back up through MD. for a weekend get together. I was riding my Nighthawk & rode every bit as hard as the others. As I said find what works for you.
Trust an Ole Fossil on the LD Shorts they are great. Handwash in the hotel sink at night & they are dry the next morning.
