Until you use a backrest you don't realize how much you slouch when you ride. It will change everything. First trip with mine I did 720 in a day with no problem. Also what somebody else sorta said, don't put a wallet or anything else in your back pockets

 

I recommend checking fit for handlebars. My stock RK bars just about killed me. Until I found some that came back to me ( I have short arms) and let me sit upright (pins in both shoulders),. I try to sit upright and not put pressure on my lower back and ride in that "C" clamp style. You can damage your vertabrae if you hit a big bump when you are practicing bad posture. I am using Klockwerks ergo back bars. You may also want to look at helibars. they seem infinitely adjustable. you can also adjust them while out on the road - not in motion, but while stopped. I also found an electraglide standard seat - more back support, wider, more padding than the stock RK. Floor board spreaders for an extra inch seemed to help a little. I did start with the big ticket items for ergos, but the little things add up with the miles. In my mind for the kind of riding I like and my preferences, the ergos are more important to me than peak horsepower. Evaluate your seating position and your possible shift to neutral upright ergos. I find that give me better control over the motorcycle as well as fights fatigue.

 

What? Do you mean that you can actually ride without a back rest? Yea my roadglide looks cooler without the driver and passenger backrest, but do you ride for pleasure or to look cool?
Of course, to look cool what was I thinking!

 

Go to a Chiropractor, get a back rest, you might also want to try using a belt such as the one made by Best Back, works great.

 

Backrest and hotels

 

Backrest, a little stretching, core exercises (planks are great, look it up), take a break every 100 miles and walk around, ibuprofen. I have to do hotels, my wifes idea of roughing it is Holiday Inn or I go by myself. See next sentence, I don't want to go by myself. Someone said less vigorous women but I'd say more vigorous. Get her on top doing all the work!