You may want to have a look at the thread linked below. The low bar is not centered on the platform. Your wheels are not located such that their contact point with the floor is directly under the outer edge of your frame. This means that by doing some extra work, you can ensure that your robot to be as tall as possible to make it easier for you to package all your components and mechanism yet still pass under the low bar. If you get this wrong, you could be stuck on the competition field or you will have a hard time building and maintaining your robot.
http://www.chiefdelphi.com/forums/sh...d.php?t=141439