From the staff at the Trials Training Center
Written for Trials Competion News, Fall, 2004
See the end of the Double Blip article (PDF)
After you've mastered the basic double blip technique, you can add other elements, such as holding pressure as shown in the photo above.
This is a more advanced technique, used to keep the front end high over the back side of the obstacle. It may be necessary to hold pressure if there's a hole on the back side of the obstacle, another ledge or log immediately behind so that you need to keep the front wheel high, or the ledge slopes upward so that it is desirable to maximize traction to continue.
The major difference with the basic double blip is in the legs after the second blip; rather than a total rear shift of the weight allowing the bike to come up underneath the rider, the rider should push with the legs as seen in the photo. Note how the rear is compressing in this photo; this push of the legs will provide maximum traction as all the weight is on the rear and nothing on the front. Also, more body movement is needed to get the rear up onto the obstacle.