i don't think any other races have nearly the prestige of the tour de france, or else we'd know their names
i'm sure he could do well if he did a fuller schedule, but tiger loses a lot, and he's still considered the best. I think if he did do a lot of other races, and only really dominated the tour de france, he'd still be considered the best, since thats the only household bike race.
if a team only played in the superbowl, but won 6 times in a row (against the best team each year), i'd say that even though the team took a shortcut, they must be pretty damn good...