Originally Posted by Random11

Somebody in these forums, some time ago, said you should be able to ride as far in a day as you typically ride in a week. At the time, I wanted to do a century and was riding only 15-20 miles a day, but almost every day and more than 100 miles a week. I tested out that idea and with no more training rode my century--107 miles. Also, I'm 71, so I have a few years on you.. I'm agreeing with everyone else who's added to this thread. I wouldn't try to discourage you from more training, but you are already in good shape to do the 40 miles.