When I bought a Cannondale hybrid four years ago my first ride was three miles and my legs were wobbly afterward. Then I did six miles per ride for a couple of months. A couple of summers later (and after a loss of 60 pounds) I did a century while at 305 (after the ride I hit the glorious 299 but my weight came back after I rehydrated).
I herniated my back last summer just after buying a road bike, and this year I'm trying to get back to the century mark. Before I hurt my back I did have one good ride of 50 miles at just a tick over 15 mph. I've done a few 40-mile rides this summer with an average speed of 14.5 or so. I'm trying to get back to the 50 @ 15 mph and then get to 100 miles. Those are my goals for the summer.
Great thread, King!