Well here there's the Iron Butt association which you get awarded by for riding 1k miles in 24 hours
I did the Saddlesore 1000 on a 2006 R1200GS in August of 2008. 1,056 miles in 19+ hours. Columbus, OH to St. Petersburg, FL- heat was brutal, even with a camelbak. When I destinated, I could have thrown my mesh jacket against a wall and it would have stuck. Sheepskin cover over a gel pad on the stock seat. Wish they had Airhawks back then. Last few miles I was screaming in my helmet, standing on the pegs. Brutal. But a personal achievement. Bike was flawless, as they are. Took two days going back home. Doing over 1000k in 24 hours is really for sadists.
The big secret for me is that on log rides, it has to be commando. Seams of underwear seem to be strategically placed to cut off bloodflow to the femoral artery, and any bunching of fabric whatsoever seems just to aggravate that. I FINALLY accepted defeat here in Florida, and bought my first pair of mesh pants for the heat, and wear long nylon gym shorts underneath, but haven't done a long ride like that. Now, goretex boots are the whip too in the heat.
On the K100RT I still have 29 years later, I KNOW I did Ironbutts before there were Ironbutts. Miami to Columbus, OH several times. I was young, and so was the bike. To that end, when I ordered my plate back thing from my Ironbutt, I ordered two- one for my K100RT that started it all for me.
"Normal" long ride for a day can be up to 500 miles to keep it fun. Setup now on a 2011 R1200GS is an Airhawk 1/3rd or so inflated under an Alaskan Leather Sheepskin cover on the stock seat- all I need.