okay, a lurch is basically a moving bunny hop.
first,you move up to the obstacle you want to jump,about
2-3' an set the cranks like you r going to jump. next,you ride backwards about 10-15'. after this,you pedal as fast as you can an PULL UP! like yur arse is on fire. you are sitting on the seat the whole time! no seat out in front!
this is the method dan heaton used to set the world record an it works! i have jumped up a 75cm wall and this is my third day trying it out. this method not only looks the coolest,but also lets you hang on with the tire better if you dont make it up the whole way. i hope this helps. let me know if you find out any other cool tricks.

keep the peace
Dan