I finished my 50 miler, and in fairly good shape, too. It took just about 3 hours 20 minutes, which is a bit more than I expected.
I'd hoped to take it easy for the first 30 miles or so, but there were a couple of hills (one at 5 miles, and another another at 17 1/2) that were pretty stiff. Since my heart rate was up to 160 by the top of each hill, I knew I was in for a long ride. Then, to add insult to injury, there was another hill at about 30 that felt like I was riding up a telephone pole for about 2-300 yards. Oh, what fun.
Ah well - next year I'll know to spend a lot more time working on hills beforehand (it's flat enough near Unknown University that I don't see a lot of hills unless I want to).
The legs aren't too bad right now, but I can tell tomorrow will be a real treat.
Next stop - a century!