If you want to watch or participate in fast times, go at noontime on weekdays. A group does interval rides and anyone can join in. Caution, if you're a novice, learn to ride and develop good handling skills and paceline knowledge. It goes slow down the admin road part, then gradually picks up speed heading south until you are screaming going down the back side. I've hit 35 mph. Then it slows before the turn back on the admin road where you recover and it all starts again.