I have confirmation that Redbud is having a pitbike race on Friday night 7/3/09. The sign ups are at 5:00 PM. This is put on by Parts Unlimited and the link below says that it is by invitation only. Don't believe it. I e-mailed the Parts Unlimited rep. in charge to ask some questions and all he said was be there at for sign up at 5:00.
I raced this 2-years ago and they had the following classes:
10in. adult
12in. adult
10in. pro
12in pro
Red Bud MX Official Website