Hello, nice to have a forum like this! Quick intro, I am in my late sixties, started a couple of years ago, I ride a few miles in the AM and a few in the PM, every day if possible, but it is not always possible, so figure about ten rides a week, thirty to forty miles in total. I ride my 19" Athmos when feeling lazy, the 24" Nimbus when spry.
It used to be that I would have to stop because I would get exhausted. Now that is no longer the problem. Now I have to stop after about fifteen or twenty minutes max, because of seat pain. And I have some nice saddles, KH Fusion One, the thick foam Exceed Carbon. And I have real handlebars on all my unis. No dice. They all hurt. And I am not that heavy, maybe ten pounds over, for my height. How do others manage?