It's roughly a 15 mile lap with about 800ft of climbing. Find some training loops to ride that are around that mileage and climbing and try to get your times to be around an hour. We do a 9-10 man team and everyone gets 2-3 laps. When the race is getting close I'll start doing two 15 mile training rides a day to simulate the race experience. With a 5 man team your looking at 4 laps per if you guys are in it to win it.
It's a great race and fun time, we've been doing it for years.
Ya I was hoping to put a 5 man team together, but I can't talk any of my friends into it. I wasn't planning on being too competitive, but I wanted to be able to do 3 or 4 laps. I think I am going to put in a request for a team on the round an round website, if anyone will have me.