Don’t tell me to look in the manual.
What is the minimum and maximum height of the bumper from the ground ?
Look in the manual 
Specifically, <R07>A, and the definition of BUMPER ZONE
A. BUMPERS must provide complete protection of the entire FRAME PERIMETER of the ROBOT (i.e. BUMPERS must wrap entirely around the ROBOT). The BUMPERS must be located entirely within the BUMPER ZONE when the ROBOT is standing normally on a flat floor, and must remain there (i.e. the BUMPERS must not be articulated or designed to move outside of the BUMPER ZONE).
BUMPER ZONE – the volume contained between two virtual horizontal planes, ten inches above the floor and sixteen inches above the floor.
Why shouldn’t we tell you to look in the manual? That’s your responsibility. It’s a duty of being a good team member.
Now if you had said, “I looked in the manual rule <R07> but it doesn’t say whagt the bumper height is” we could reply, “It’s in the definition of BUMPER ZONE.”
that is the wrong way to start off a thread…
You should at least be able to look it up yourself.
It builds character…
smiles oh so politely 
Read “The Robot”
AKA section 8.
http://www.usfirst.org/uploadedFiles/Community/FRC/Game_and_Season__Info/2010_Assets/08_The%20Robot_RevA.pdf
try the little search bar at the top. works for sections 1-10. Amazing right? Have fun with it 