I piddled around trying to navigate through three metroparks in SE Michigan that are linked by a paved bike path. The bad news is I ran out of bike path while going north into the higher metropark, but the good news is I wound up in a low traffic area (Romulus, MI) ... so kept riding on Huron Drive around the Romulus area of Metro Airport ... before backtracking to the bike path that goes into the two lower metroparks.
I fueled up with a large order of french fries and three large diet cokes (burp) at a Romulus Burger King, and got my second wind. Having not ridden in a week, my leg muscles seemed to have been fresh enough to take the distance. Total time from beginning to end of ride was about five and a half hours, but my computer for some reason lost its accrued average speed for the 270 collective miles I ended with today on my new bike. Today's distance was 52.7 miles and I recently turned 51, and I would guess that my average speed today was around 13 MPH.
I'm currently experiencing a comfortable pain in my leg and back muscles ... sort of like the saying "hurts so good". May be an endorphin high, that I've heard about from strenuous activity.