Bumper height

[litterClean]

The concern is that according to the rules, the bumpers appear to need to be at least 2" off the ground (http://frc-manual.usfirst.org/viewItem/181#4.1) (r25). That said, our robot is only about 2.75" off the ground as the wheels are 6" in diameter, which puts the fasteners at the bottom most edge of the wood. Is that rule hard set or can we put it just 1" or .5" off the ground? Obviously ground clearance is ideal, but we want to make sure the bumpers dont break off.