Here's the deal... Build one of these http://www.instructables.com/id/Gravity-Bike/ using an existing bike or from scratch. 20" wheels only. Make it ratty and stylish as you can BUT you must post a video or photo proving you rode it using gravity only at a speed of over 35 MPH before September 12 (my birthday. If there is any interest, I will post up my before photo here and follow with a build. If not, I'll start a regular build thread. Come on and join me. I double dog dare you!