It’s been a long racing season for America’s mountain bikers. The NORBA National Championship Series is over, as is the UCI World Cup; the world titles were decided last week.

But it’s not time to hang the bike in the garage - not with the 2005 U.S. mountain-bike national championships scheduled September 15-18 at the Mammoth Mountain ski resort in California.

Though other national championships are long since in the books, the U.S. national championship remains, the last major fat-tire race of the year.

This doesn’t exactly make everybody happy. Since the NORBA season kicked off in early March, riders are in their seventh straight month of racing, and more than a few of them are running on fumes.

Big Bear Productions, which organizes the NORBA series and the national championships, recognizes this, and thus the 2006 national mountain bike championships are scheduled for July - a full two months before the world championships - in their third and final year at Mammoth.

Meanwhile, this year’s riders are getting a break of sorts, too. The 2004 nationals were held at Mammoth's main lodge, but this year’s edition is based at the Canyon Lodge, nearly 1000 feet lower in elevation.

Cross-country: Men

Racing a little farther down the hill could affect the outcome of the cross-country races. Last year’s 11.1-mile course featured a brutally long climb that took riders well above 10,000 feet. This year’s 6-mile lap serves up 1400 feet of climbing per lap, but never climbs that high. Men face four laps, women three.

In the men’s event, the loss of elevation could work against 2004 champion Jeremy Horgan-Kobelski (Subaru-Gary Fisher), regarded by many as North America’s top rider at altitude. JHK owned last year’s cross-country, finishing a whopping two minutes ahead of second-place Adam Craig (Giant).

Not known for his abilities at altitude, Craig is nonetheless enjoying his best form this year, and is the top candidate to give JHK a fight for the title. He was the top American rider on the World Cup circuit, finishing seventh overall, and scored an impressive 21st at the world's despite flatting. The 24-year old holds a pair of U23 national cross-country titles and would like nothing more than to add an elite championship to his collection.

Dark horses include: Barry Wicks (Kona-Les Gets), who won the Cougar Mountain Classic cross-country on September 10; Jeremiah Bishop (Trek-VW), the NORBA marathon and cross-country star; Carl Decker (Giant), the 2005 elite road champion; and Walker Ferguson (Scott), the 2000 junior cross-country world champion, making a comeback after more than a year off.

Cross-country: Women

Expect a duel between teammates - 2005 NORBA overall winner, Shonny Vanlandingham, and 2004 national champion Alison Dunlap, both of Lunca. Luck may determine the winner, since both Vanlandingham and Dunlap thrive at altitude, and both are motivated. Vanlandingham has never won a national championship, and Dunlap – who will be racing in the final event of a long and storied career - would love to go out with a victory.

Vanlandingham peaked for the world's, so the edge could go to Dunlap, who skipped world’s to train in Colorado. Dark horses include 2005 NORBA race winners Heather Irmiger (Tokyo Joe’s-Go Lite) and Dara Marks-Marino (Ford Cycling), both of whom excel at altitude; cross-country favorite Willow Koerber (Subaru-Gary Fisher); and short-track specialist Susan Haywood (Trek-Volkswagen).

Gravity games

For the gravity events, organizers put together three individual courses: the bullet, follow-me and the Kamikaze. The bullet, for professionals and experts, follows Mammoth’s usual speedy 1.4-mile downhill course. Tthe follow-me, for beginner and sport riders, features less vertical but more twists and turns. And the famed Kamikaze carves a nearly straight line from the mountain’s summit to its base.

Barring an injury or serious crash, Luna’s Kathy Pruitt should easily take the women’s race ahead of April Lawyer (Maxxis) and Melissa Buhl (KHS). In the men’s competition, 19-year-old sensation Duncan Riffle (Yeti) hopes to defend his 2004 title against strongmen Chris Van Dine (GoRide) and Cody Warren (Haro).

Warren is also a favorite to take the mountain-cross, but he’ll have to take down 2004 world champ Eric Carter (Hyundai-Mongoose), whose 2005 season has been marred by injuries. Still, when EC is firing on all cylinders, only a select handful can keep up.

Recently crowned world champion Jill Kintner (Yeti) is the odds-on favorite for the women’s mountain-cross title, but she’ll have to dethrone last year’s winner Tara Llanes (Giant-Pearl Izumi) first.

The four-day national championships kick off Thursday with the marathon, which will send riders on a 100km slog across Mammoth Mountain. Look for a tight men’s race among Olympian Travis Brown (Trek-Volkswagen), 24-hour solo king Chris Eatough (Trek-Volkswagen), and distance kings Mike Janelle (Tokyo Joe’s-GoLite) and Jay Henry (Ford Cycling).