By Rob Miech

Thu, May 1, 2008 (2 a.m.)

The weekend motocross extravaganza starts small Friday night inside Orleans Arena and ends with a bang Saturday night outside at Sam Boyd Stadium.

At the Orleans, the little things will matter in the Maxxis MiniMotoSX 2008. Those are the minibikes, or pocket rockets. Kids and adults will jump and hop around the horseshoe building for $15,000 in prizes.

At Sam Boyd, the big boys take over in the final event of the AMA Supercross series. Organizers have promised to build the most demanding course in the history of the event.

Here’s what, and what not, to expect:

1. The little ones

We’ll keep a close eye on the MM10A, the amateur 13- to 17-year-old class with the 10-inch rear wheels, and unlimited engine modifications, at the Orleans. They’re inexperienced and there are plenty of moguls to soar over. Kids, keep the machines in the arena.

2. The big ones

The MM35+ class should be interesting too. These are the older guys on those tiny bikes. Something’s gotta give. The MiniMoto will feature 700 racers, 160 starts and 16,000 racing laps. Bring an energy drink or two and get seats in the horseshoe end — four jumps down there will provide high entertainment.

3. No Carey Hart

Unfortunately, the longtime Las Vegas native won’t be racing at Sam Boyd. He’s broken 63 bones on the tracks and is a walking Vegas billboard, with tattoos on one arm devoted to the city. His wife, entertainer Pink, filed for divorce in February. So what if he isn’t racing? Can’t talk about motocross in this town without mentioning Hart.

4. The rivals

Chad Reed, No. 22, leads the Supercross series with 340 points. He’s from Tampa, Fla., and is gunning for his second series championship. Three weeks ago, he cracked a shoulder blade in Detroit. Mississippi native Kevin Windham, No. 14, trails Reed by 10 points. Their fans have bitter words for each other.

5. The track

Supercross organizers have concocted a unique layout for Saturday. The 825-foot starting straightaway will begin out of fans’ view, and a flat track will wind outside the north end of the stadium. The 75-second laps will be the longest in the series, and there will be new jumps and rhythm sections — is this a race course or a brass band?