I often do 30-40 mile rides on my 2013 Fuji Absolute 2.1, and it gets most of my saddle time. I'm a 52 year old Clydesdale, and also enjoy riding a 1974 French-made Motobecane Grand Touring that I restored and rebuilt. The Motobecane's geometry isn't as severe as many modern road bikes, but the reach is ever so slightly too long for me. Until I can replace the stem, I'm riding the Fuji most of the time. I'm not worried about keeping a 20mph pace keeping up with anyone, and most of my rides are solo or with a friend riding at conversation speeds. My primary goal is fitness and to help manage my Type 2 diabetes, and it's great for that. My current goal is 50-60 miles in a rolling 7 day period, and so far that's not an issue. I'll normally do a couple of 8-10 mile weeknight rides and longer rides on the weekend. Don't let others tell you what you can't do on your own equipment.

Cheers.