Thanks!
I don't think I will hit the wall on this 50. I have done a 50 once before, but maybe not has hard as I plan to do this one. Good advice on trying the bars before the ride, as I have kind of a sensitive stomach.
The rides are 10, 25, 50, 65 (metric Century) and 100 miles that day. I wish they are were continuations of each route, but they are all different, so if I hit 50, I can't decide to continue on and do 65. So I decided to start in the middle. The 25 is not much more than I do every day.
If anyone in Northern VA is interested, here are the details of the ride.
http://valleyrallybikeride.com/