A ride past a unique landscape: red sandy desert, white salt lakes, flamingos, vulcanos. The track you have to cope with is quite rough and sandy but it is definitely worth every drop of sweat!
The complete tour is in heights between 4000 - 4950m. Prior acclimatization is important.
During the season there are daily 10-20 Jeeps with tourists travelling along that route. They can help in case of an emergency.
There is no rescue organisation in Bolivia! If you cycle this route, you have to be fit and careful. Illness or an accident can get you in serious trouble!
For the section from Laguna Blance to the Salar de Uyuni you should plan with at least 5-8 days.
The road until Laguna Colorado is quite ok. After that, it gets sandy with washboard. I had to push the bike for totally 15km (can be very hard in deep sand). Daily stages of 30-50km are realistic.
During the season there is mostly a clear sky. Temperatures during the day are quite comfortable. I used to cycle in long windstopper cycling pants, shirt and gloves. In the afternoon there is often a strong wind (mostly coming from W or SW). At night the temperatures drop to -15°C, a good sleeping bag is important.
One of the main problems of this route, is the water. Water is available at the Campamentos at Laguna Blanca and Colorado, at the Campamento Corina and in Chiguana. I doubt, that you can drink the water of the different Lagunas, although I did not try it.
The longest distance with no water is from Laguna Colorado to the Campamento Corina (100km, 3 days) or to Chiguana (160km, 3+days). I carried 18 liters of water for this part!