Interpretation ID: 1982-3.29

TYPE: INTERPRETATION-NHTSA

DATE: 12/08/82

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Don Vesco Products Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of September 15, 1982, asking about the legality of "covering of a headlamp on a motorcycle with a clear cover."

You reported that manufacturers of motorcycles and fairings are producing such covers. The National Highway Traffic Safety Administration views this practice as prohibited and will take appropriate steps to make it views known. The legal authority for this is based upon a requirement of the SAE incorporated by reference in Motor Vehicle Safety Standard No. 108 or, alternatively, paragraph S4.1.3 of that standard.

SAE Standard J580 (both a and b versions), Sealed Beam Headlamp Assembly, is incorporated by reference in Tables I and III of Standard No. 108 as one of the standards pertaining to headlamps for use on passenger cars, trucks, buses, and multi-purpose passenger vehicles. A paragraph in each version states that, "When in use, a headlamp shall not have any styling ornament or other feature, such as a glass cover or grill, in front of the lens." SAE J580a applies to all sealed beam headlamps, while the scope of J580b is considerably narrower, including only those not covered by SAE J579c.

The principal referenced SAE material for motorcycle headlamps is J584a Motorcycle Headlamps. As options, both J584 and S4.1.1.34 of Standard No. 108 allow, in effect, a motorcycle to be equipped with one half of any sealed beam system permissible on four-wheeled motor vehicles.

Paragraph S4.1.3 of Standard No. 108 forbids the installation of additional equipment "that impairs the effectiveness of lighting equipment required" by Standard No. 108. Because of moisture accumulation, discoloration, cracks, etc., a glass or plastic cover might tend over a period of time to diminish or distort the headlamp beam. This is of particular concern with reference to the unsealed headlamps implicitly permitted by SAE J584 because of the tendency of the reflector to deteriorate with age.

For the reasons stated above, the agency has concluded that no headlamp may have a glass or plastic shield in front of it when in use, regardless of the type of vehicle on which it is used.

As for the turn signals, no part of the vehicle may impair their visibility through horizontal angles 45 degrees to the right and left of the vehicle (for right and left turn signals respectively) measured at the longitudinal axis of the vehicle. An unobstructed illuminated area of outer lens surface of at least 2 square inches excluding reflex is necessary to meet this requirement. You will have to judge for yourself whether the turn signal requirements are met with your planned cover in place.

If you have any further questions, we shall be happy to answer them.

SINCERELY,

DON VESCO PRODUCTS, INC.,

September 15, 1982

OFFICE OF THE CHIEF COUNSEL NHTSA

To whom it may concern;

We are a small manufacturing firm and we produce various motorcycle products. Our main product at this time is a motorcycle fairing as shown in the photo on this letterhead. I am in the redesign stage of this fairing and would like to produce a product with flush fitting turn signals and possibly a covered headlight. I cannot find any D.O.T. specifications on the covering of a headlamp on a motorcycle with a clear cover. Many motorcycle accessory companies are producing fairings with this feature and, at least two motorcycle manufacturing companies are producing motorcycles with this feature. I have enclosed a number of copies showing the headlamp coverings as now produced.

What I want to know is what specifications are required to add this feature, or, is there simply nothing stating that such a feature is permissible?

I also would like to know what specifications will be required to add a clear covering over normal D.O.T. approved turnsignals. I can find no ruling that in any way prohibits or even mentions any clear covering that does not interfere with the operating of the lamp or the visability. We have limited funds and cannot afford to tool up for a special flush fitting turnsignal. However, our experiments have added up to a 23% increase in fuel economy on our test motorcycle using the new design and we feel that the commuter can use any gain possible. A 23% increase in fuel economy with no mechanical changes and only aerodynamic improvements is significant.

Time is of the essense. We must have some information on this within the next 4 weeks. Thank you for your cooperation.

Matt Guzzetta, Vice-President