It took 2 days to cycle from San Pedro to the telescope. It was possible to cycle most of the way to 5400m and then we had to push the bikes. From the telescope we summitted in a couple of hours and descended back to our bikes. From here we pushed the bikes south towards Licancabur and descended on a little used track with views of Laguna verde. We carried all our water from San Pedro because the water on the peak is contaminated with sulphur.
For more info: http://pikesonbikes.com/traversing-sairecabur/
2.5 miles round trip from trailhead at 18392 feet to summit at 19758 feet (6022 meters by Garmin eTrex Vista HCx GPS) and return. From truck to summit and return took nearly 7 hours. Not easy, but well worth the effort for the views of Licancabur and into Bolivia.
Easy hike up with guide Christian and two Chilean miners Rene and Jose. I was acclimated from my travels in Peru and Bolivia so had no problems tagging the summit. Amazing views into Chile, Argentina and Bolivia. My first 6000m peak (though there is debate about whether or not peak actually measures 6000+ meters.