Evans in driver's seat heading into Saturday's time trial

The beauty of the Tour de France is that it's all about the overall rider after three weeks.

You can be a great climber and dominate the mountains or be a solid sprinter, but you still need to be an above-average time trialist to win it all, or, at least, make it easier on yourself to win it all.

I think we've been spoiled over the past decade by riders like Lance Armstrong and even Jan Ullrich, riders whom we saw finish so well in both the mountains and time trials. Now, we're in a specialist phase, where we see riders excel in either sprints or climbs.

Which brings us to Saturday's all-important time trial, which, just as Tour officials had hoped with its new format, will decide this year's winner in what has been a wide-open race up to this point.

My Team CSC-Saxo Bank teammates, Carlos Sastre and Frank Schleck, sit 1-2, respectively, in the general classification going into the 32.9-mile Stage 20. And, on paper, they are two of the world's best mountain climbers. Time trials are not their forte.

How will they and the other contenders perform with so much on the line? Here's my breakdown for the top six riders:

Carlos Sastre and Frank Schleck

If you look back at Carlos' past few Tour time trials, he finished 16th in 2007 (losing 2:50 to Evans in the penultimate stage to finish fourth overall) and 19th in 2006. But that doesn't mean he's incapable of riding a strong trial (he's done better in time trials at the Vuelta a España). It all depends on which Sastre will show up Saturday.

My advice to Carlos and Frank over the years has been to try to concentrate more on the time trial bike. They both have a huge gift when it comes to climbing, but you need to do more than climb well. Have they done enough to really dial in and train enough for a time trial, enough to be ultraconfident heading into Saturday? That's why it's going to be more mental for them. I hope my teammates come through. They have the best equipment and good positioning in the overall standings. They'll have to ride the time trial of their lives. They deserve a shot at the podium as much as anyone given their work and sacrifice over the past weeks.

Bernhard Kohl
The second- and third-place podium spots are wide open, but my worry for Kohl is that he may have expended too much energy in the mountains. For a rider as small and skinny as him, it's impressive to win the best climber's jersey. But will he be strong enough in the time trial?

Cadel Evans
Evans is dialed in and is the favorite heading into Saturday's stage. He showed a little weakness compared to the pure climbers in the mountains, but his overall strength is he's a general classification rider. He can climb, limit his losses in the mountains and then do well in a time trial. He's done a lot of work on his position; all of his equipment has been looked at and analyzed. Position or not, though, it's freshness that matters in the final week of the Tour. Cadel is a fighter, always has been. You have to respect that about him. He was a prerace favorite and here he is, challenging for the overall win, and he did it with basically no help from his team on the road, especially in the mountains. That says a lot about a rider.

Denis Menchov
From what I've seen, he could reach the podium. But he's been suffering in the mountains. Does he have it in him to do the kind of time trial he needs Saturday? We'll see how he's recovered.

Christian Vande Velde
He's got one of the best positions out there and has the right mentality for the stage. The way he's performed in time trials this season, I don't see any reason why he won't be right there for the stage win, if not a podium spot. He is a natural, aerodynamic rider and knows how to pace himself. Plus, Vande Velde has only gotten stronger throughout the Tour. For a guy who's been thinking about limiting his losses over the race and eyeing this time trial, he's in the mix. If he can move up from sixth to the podium, it would be amazing. He deserves it with the way he's performed. As I said earlier this week, it's just a shame he lost time after crashing during Stage 16's final descent.

Preparations and predictions
Before the start of Saturday's stage, riders and teams will go out and see the entire course one last time, previewing every turn. They'll also make sure to eat right and relax a bit before warming up.

During the stage, riders will be pushing their watts and listening for updates from the race radio. For me personally, the radio always hurts. When I am in a time trial, I am going 100 percent regardless of what else is going on. When I am putting everything out on the line, I don't need someone to tell me to shift down or up, or pedal harder. But for non-time trial specialists like Frank and Carlos, who will be the last two riders to hit the road in Saturday's stage, the information they receive, and how they deal with it, is going to be crucial. If you know you're going to your limit, and you hear you're behind the pace, that's tough to hear.

CSC has done everything it can do at this point. I think some people were waiting for some kind of CSC attack over the past few days. Even though that didn't come, riders were spinning their legs and recovering as much as possible in preparation for the final time trial.

Now, it's mano a mano, and it's going to be a mental game. There are going to be some nerves, for sure. Some riders have prepared and know they've done the work to get a good ride; others will question themselves on the course ("Do I have the right wheels? Am I in the right gear? Am I doing as much as I can?").

Overall, Evans is in the driver's seat unless Sastre can surprise us with an amazing time trial. History has shown us that when Evans is under pressure, he's very strong. The top six riders all deserve a shot at the podium; it's going to be that mental edge in the last 20 kilometers that tells us who will win it all. My pick would be Evans, Vande Velde and Menchov going 1-2-3 in the stage. Will their times be enough to change the podium positions? I don't know. It's totally unpredictable.

But they'll be fighting for a chance at that view from the podium in Paris. It's a view not many get to see.

Bobby Julich, a member of Team CSC-Saxo Bank, will be providing a diary for ESPN.com throughout the Tour de France. The American has been a professional cyclist since 1992. He finished third overall in the 1998 Tour de France and won the Paris-Nice race in 2005.