Professional Cycling - Questions on some Tour strategy

So today, Rasmussen's dragging a Astana guy and a Caisse guy up the hill. The announcers mention that these guys are not going to help out because their leaders are back in the peleton. So, my questions are:

1. By following Rasmussen, are they causing him problems? I.e. are they slowing him down? For the same speed, do you use more energy (compared to soloing) if someone is drafting you?

2. Why aren't they back helping their leaders up the hill, like Kloeden did for Vino?

3. Why wasn't Contador helping Levi up the hill?

Thanks,

1. If they made it to the finish with him, they would jeopardize his chances of taking the yellow jersey and/or the stage win. Therefore its supposed to discourage him from continuing and giving out a "free ride". Luckily, he was strong enough to drop them both.

2. altering the strategic situation by getting into a break can be just as valuable as pacing right in front of your captain.

3. same as the other men with GC guys behind them, or he could have decided to ignore the radio and ride for himself.

3. because levi didn't need help. he explained that today's team assignment was for Popo and Contador to get into a break and for him to hang out and watch the other favorites. Considering that this is exactly what happened, I assume everyone is happy... well, except Contador after that untimely flat.

So today, Rasmussen's dragging a Astana guy and a Caisse guy up the hill. The announcers mention that these guys are not going to help out because their leaders are back in the peleton. So, my questions are:

1. By following Rasmussen, are they causing him problems? I.e. are they slowing him down? For the same speed, do you use more energy (compared to soloing) if someone is drafting you?

2. Why aren't they back helping their leaders up the hill, like Kloeden did for Vino?

3. Why wasn't Contador helping Levi up the hill?

Thanks,

Eggs, baskets

The person getting drafted gets somewhere in the area of a 5-10% bennifit from having someone on his wheel. It is the same principle of the curved seattube paired with a disk(there is lessened air turbulance in the middle of the bike). So with the riders, the second rider is completing the aero profile, so the drage caused by the air curving around behind him is on the guy in the back, but due to the bennifit of not breaking that air, they are still getting about a 30-35% bennifit.

3. because levi didn't need help. he explained that today's team assignment was for Popo and Contador to get into a break and for him to hang out and watch the other favorites. Considering that this is exactly what happened, I assume everyone is happy... well, except Contador after that untimely flat.

Further, Levi also said he had two men helping and they wanted Contador to shake things up.

The person getting drafted gets somewhere in the area of a 5-10% bennifit from having someone on his wheel. It is the same principle of the curved seattube paired with a disk(there is lessened air turbulance in the middle of the bike). So with the riders, the second rider is completing the aero profile, so the drage caused by the air curving around behind him is on the guy in the back, but due to the bennifit of not breaking that air, they are still getting about a 30-35% bennifit.

OK, if that's true (and I've hear that before), weren't the Astana and Caisse rider actually helping Rasmussen? Shouldn't they have let him go by himself, if all they cared about was the team?

It was far more important to 'keep him honest' and not let him get a free break. They were banking on hanging his wheel and sniping him, which would've worked, had Rass not been strong enough to drop them.