Interior Rearview Mirrors
“Shortly after I wrote my last post concerning exterior rearview mirrors, I got a call from one of my I-Car training colleagues asking a question about interior rearview mirrors. His question concerned the portion of the standard which he felt required the mirror be released from the mounting pad by the airbag deployment. I corrected him about the airbag part of his inquiry because the airbag is not in the standard.” —Bob Beranek
S5.1.2 Mounting. The mirror mounting shall provide a stable support for the mirror and shall provide for mirror adjustment by tilting in both the horizontal and vertical directions. If the mirror is in the head impact area, the mounting shall deflect, collapse or break away without leaving sharp edges when the reflective surface of the mirror is subjected to a force of 400 N in any forward direction that is not more than 45° from the forward longitudinal direction.
The 400 N represents 400 newtons, which is a measurement of force which is close to 90 lbs. (to be exact 89.923577548 lbs.) This means that the interior mirror is required to be released from its mounting by a force of 90 lbs. This is to protect the occupants from injury by the rearview mirror and/or mounting in the case of a collision. The older mirror mounting were so firm that serious injury was caused not by the windshield but by the mirror mounted to the windshield. So vehicle manufacturers had to build their vehicles with “break-away” mirrors since the 2000 model year.
The above are the facts related to interior rearview mirrors according to the Federal Safety Standards, but the reality of true mountings is something that confuses me. As a technician who has removed thousands of supposedly “break-away” mirrors, I find it curious that there are so many mirrors that take special tools, techniques and plain brute force to remove from the pad. There are ¼ turn mirrors, underside clips and others that take a concerted effort to release. Do these mirrors meet the requirement of breaking away by 90 lbs.? Shouldn’t they just pop off with upward or downward pressure of 90 lbs. or more? You would think so, but I fear that the standard isn’t being enforced.
There are still plenty of mirror mountings that do meet the standard. What happened? Did designers and engineers bow to the demands of consumers who complained of loose or vibrating mirrors? What about the federal government standards? Like all government agencies, they are dependent on the funds budgeted. If government doesn’t have the money to hire analysts and auditors to keep track of minor infractions, they depend on corporations to regulate themselves. They may require reports to be filed, along with data to prove the reports, but is the manpower available for follow-up? I believe that like so many other things that fall between the cracks, the rearview mirrors in automobiles are not on the government’s safety radar until serious injury occurs.
What do I believe? I believe that mirror designs work on paper but not in reality. I believe that the government regulators mean well in writing safety standards but don’t do well in enforcing them. I believe that mirrors are supposed to be removed relatively easily, but we still need tools, techniques and brute force to remove them.
So to my friends that suffer through the rearview mirror removal of automotive glass installation, you have my sympathy. I doubt seriously that the mirrors will automatically be easier to remove in the future. On the contrary, I believe that they will be harder to remove because the customers demand for firm mountings and fewer vibrations. But keep you hopes high, we always come through with innovative ways to get the job done.