So, I am planning on doing my first century ride in 7 weeks. I have done a metric century, and feel pretty good about my riding and my ability to get into condition by the time of the event. My question is, what kind of schedule should I be doing to prepare? I haven't been able to ride more than 3 times a week, and I haven't been doing a whole lot lately...20 mile rides mostly. I know I should be up to doing a 70-80 mile ride about a week before the century, but how should I be working up to that?