That first one you linked.... I used to jump way, way, WAY farther than that when I was 13-14. I never wiped out. I let my buddy try it, he did. It's still an occasional joke between my sister and myself, "Oh goddamn!" sailing through the air, then he lays it down and bends my forks on a pine tree. Stands up dazed and in shock. I showed him how to do it and warned him about the danger. He wasn't seriously hurt, though. It was dirt. edit: actually, it wasn't "oh goddamn," it was "OH! GOD DA-A-A-A-A-A-A-A-A-AM-M-M-M-MN!!!!" There was a trick to getting really airborne and I explained it to him. Unfortunately, he understood that part, but he forgot the part about hit the back brake right after you hit the ground or you will be in a stand of trees going 60mph. I think he was just not ready for the feeling of being that high in the air, moving that fast toward a wall of trees. Also, I did it once with him on the back, and so we didn't launch as far, so he wasn't expecting what happened when he was solo.