Here are five supercross riders newcomer James Stewart will have to get past to rule the 250-cc series
Ricky Carmichael, 25, AMA ranking: No. 1
If he doesn't injure himself, the 40-time winner will take his fourth AMA supercross title this year.
Chad Reed, 23, No. 2
With 21 career wins, the Australian is the sole rider who can still challenge Carmichael for the 2005 championship.
Kevin Windham, 27, No. 3
This supercross vet stole the season-opening showdown from Carmichael and Stewart on a muddy track.
Jeremy McGrath, 33, No. 17
The seven-time supercross champion came out of a two-year retirement but has yet to win this season.
Travis Pastrana, 21, No. 27
The notoriously fragile rider had another setback when he suffered cuts to his legs in a crash last Saturday.