I'm getting into randonneuring and only have done a 200k, although I've also ridden a couple 150 milers with my local club. The thing that always stops me isn't my legs or fatigue... but my butt. I have experimented with 5 different saddles, and it seems that something is rubbing against me until it hurts so much that I cringe and bear it until the end of the 150. I weight 188, so I don't think it's my weight. I've also tried shammy lube, but I've never carried enough around with me to keep refreshing it.
I'm thinking perhaps an aero bar will help because my friend who uses them tells me that for long rides, it can be used to take weight off your butt. Sure, I can stand, but I can only do it for so long.
What do you guys think? Do aero bars help with long distance, especially when my limiting factor is sitting for too long.