The following is from the July/August 2007 issue of Today's Tire Industry:

Q.   I have been told that the tire inflation safety cage must be 12 inches from the wall or flat surface. Is there a regulation that requires this?

A.   The regulation does not say that the inflation cage must be 12 inches from the wall. It states that tires shall not be inflated when any flat solid surface is in the trajectory and and within one foot of the sidewall.