Vuelta is gonna get a pretty strong field, as usual in the last few years. I'm assuming a bunch of the top guys from the Tour will be there on a 2nd peak, which is usually a little lower and a bunch of others will come relatively fresher after Giro + Olympics. Contador would likely tier 1 contender coming in relatively fresh. Its hard to predict how these levels compare to each other. Often you see the guy's coming from the Tour being slightly off their Tour shape, and being more susceptible to having a bad day. Especially on the hardest stages. I think freshness is more important for those, then for the typical unipublic stages. Looking at the parcours, there's only one multi mountain stage, so that should help those who come off the Tour.
Looking at the parcours, the strongest climber will win. Being relatively better at steeper and shorter climbs is an advantage. The tt will be all about who's got the most energy left.
I don't really know how the Olympics will affect this, however. It makes me think doing that double will be even harder. There are 26 days between the End of the Tour and the start of the Vuelta. This was also the case in 2012. However, in 2012, the Olympics started the weekend after the Tour. This year, there's an additional week between the Tour, and the start of the Olympics, so the road race is square in the middle between Tour and Vuelta.
We don't really have reference to how this affects a double attempt. Froome tried in 2012, started in a little bit less form than in the Tour, and then completely ran out of gas in the third week. This is the only reference we have. Some factors are completely different however.
- Preperations for doing all these races are likely more specific
- Peak in Tour will be later
- They'll likely go deeper than in Froome did in 2012
- More travel, possible jet lag
- Different early season, Froome didn't do much in the spring, but then in 2012 he did even less. Same goes for Purito for example. Quintana raced quite hard in the spring.
- I'm probably missing some stuff as well.
Al in all, this 10 week period will be super hard on those riders. They'll have to their peak in the 3rd week of those 10 weeks, and then hold it throughout the recuperation period between the GTs to compete in the Olympics, all the way to the end of the third week if they want to possibly win the Vuelta as well.
If you then look at what Contador has to do for the Vuelta, it's rest and recover > train > race prep race > train > go to Vuelta. Unless the likes of Chaves, Superman, or Kruijswijk reach a level we haven't seen of them before, Contador has to be the favourite, assuming he won't ride the Olympics. If it goes well, I'd say 2-3 stage wins.