[adouglas]

You nailed it when you said you do not move around on purpose.

Sit in any firm chair without moving for two hours and what do you expect?

A few years back I did a long tour on my Ninjette (2600 miles, give or take). At the time I was having knee issues and was actually using a cane to walk. Had a lot of seat time to ponder what was, and what was not, comfortable.

The two key findings were a) stopping and getting off the bike once per hour really helps for long-term comfort. Just a minute walking around will do... and b) sitting still is really bad.

I also concluded that getting your weight off your butt is a good thing. The most comfortable position was to lean forward and shift my feet back, to get the weight onto my thighs. Leaning on the tank with your belly/chest. But, as above, don't just lock into that one position... move around and change it up.

Try this on an upright chair. Sit normally, upright with feet flat on the floor. Feel how all your weight is concentrated on your butt.

Now scoot forward so you're perched on the front edge of the chair, leaning forward with your feet tucked back underneath a bit. See how all the weight has come off your butt and is now on your thighs?

Think about how a jockey rides a race horse. Kind of like that.

After that tour I got clip-ons and rearset adjusters to give the bike more sportbike-like ergos. My butt hasn't been sore since, not even once.