Be aware it is dangerous! - Our experience was very good initially when we climbed Cotopaxi and came down. Things started to go wrong when we were asked, out of the blue, to sign a consent form for the use of bikes, saying that whatever happened to us was our responsibility and that they were not forcing us to use the bikes. A few minutes later we were on the bikes. We were not told how dangerous and steep it could be going down and straight away I saw many people of my group losing control of the bike and going downhill at max speed. I am a reasonable bike user and a few moments after going down I noticed my left break was not working properly. I was really struggling keeping control of the bike due to the steep descent and the brittle terrain. A minute later in front of me one of our group had badly fallen from his bike and was unconscious. I am a doctor and went to help. When I was there the guy started having a seizure and it was very difficult to control it in the middle of the road. No passing by cars wanted to help and everybody drove away. They guy was losing blood and I could see a massive injury under his helmet, which obviously I did not remove. I will avoid other very scary details of his presentation but I can assure it was all very scary, considering we were not receiving any help and the closest hospital was hours away. He re gained consciousness after a few minutes. Everybody wanted to remove his helmet and I had to fight with people to discourage this. Eventually they removed his helmet anyway. They did not want to bring him to hospital as they said he was conscious and well at that point. Again I had to fight for this. Fair to say it was a shocking experience and I wish the group had been warned before about the dangers. We were not told a word. But I guess the fact they make you sign a consent means incidents like this happen frequently. I would like my review to be helpful to other people like me. People please be careful. Don't do what I did and consider all the risks.