The rope-climbing obstacle in Spartan Races is one that a significant number of people fail.  Like other obstacles, technique can be the most important factor for determining who makes it to the top and who wears themselves out in the burpee penalty box.  The rope climb was fairly easy for me prior to my shoulder injuries, but since then I have struggled at times due to the loss of strength on my left side.  Obstacle racing is all about adapting and that is what I’ve done.  I bought a rope.  I searched all over the nether regions of the Web and found a technique that works for me…..and works quite well.  The technique is not uncommon, so don’t expect it to shock the world.  Rather than try to describe it with words, I decided to video it.  Here it is.  Good luck!