Yeah, looks like one of the carbon graphite whatever frames. Our terrain is mercifully flat. Mine is a Schwinn 7 speed and I never take it out of 7, cause I want max muscle test; no pesky inclines to try me. My max mileage 8. So I’m nowhere near you guys’ league.
Discussion
The milage isn't as important as the amount of effort exerted. I've ridden 25-50 miles in lower gears throughout the day and not felt as tired as I do when I bike 10 miles all out on the second highest gear. 🤷
I wish we had a mountain. That would be the best exercise on a bike.
I grew up in Birmingham on a hill with the most brutal pitch. Riding a bike on it was not my favorite. If it iced over during winter storms, no getting up or down without snow chains.