Originally Posted by
Carbonfiberboy
Nah, I never could. I always stop, rest, pee, and refuel about every 3 hours, max. That said, back when I was about the OP's age, I rode STP (a double) at a rolling average of 19.9, though my ET was only a hair under 12 hours.
I only pay attention to the moving time. IMO, all the rest stops should be neutralized. Much more civilized.
I've never done a double, but the last time I did Climb to Kaiser (155 mi, 14,000'), my moving pace was 17.5 mph. For a hot and hilly ride, I figure that's fast enough.
Nowadays, I start to get bored at about ~4 hours, so centuries are out.