Interpretation ID: 1984-2.37

TYPE: INTERPRETATION-NHTSA

DATE: 07/24/84

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Koito Mfg. Co. Ltd. -- M. Iwase, Manager, Techinical Administration Dept.

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. M. Iwase, Manager Technical Administration Department Koito Mfg. Co., Ltd. Shizuoka Works 500, Kitawaki Shimuzu-shi, Shitzuoka-ken Japan

This is in reply to your letter of June 21, 1984, to Mr. Driver of this agency asking for an interpretation of Motor Vehicle Safety Standard No. 108. Mr. Driver has not been an official of this agency for many years, and in the future, your requests for interpretation should be addressed to the Chief Counsel, National Highway Traffic Safety Administration.

Your first question is whether Safety Standard No. 108 permits a two-headlamp system on motorcycles. The answer is yes. Paragraph S.4.1.1.34 specifies the lighting systems permissible on motorcycles. It allows two Type 2D1 or Type 2 (7 in.), or two Type 2B1 or Type 2B headlamps. Under Table IV, if two headlamps are used, they must be disposed symmetrically around the vertical center line. Two non-sealed headlamps meeting the requirements of SAE J584 may also be used, subject to the same mounting restriction. Therefore the system you propose appears acceptable under Standard No. 108.

You have also asked whether the two headlamps may be mounted one atop the other, rather than side by side. While Table IV specifies that a single headlamp must be mounted "on the vertical centerline", requires that two headlamps be disposed symetrically around it. We do not interpret this language as allowing two headlamps to be mounted adjacent to each other on the vertical centerline.

Sincerely,

Frank Berndt Chief Counsel

Air-Mail

Mr. E. T. Driver, Director Official of Crash Avoidance Date: June 21, 1984 Motor Vehicle Programs U.S. Department of Transportation Koito Ref. No.84.06.21.02 National Highway Traffic Safety Administration Washington, D.C. 20590 U.S.A.

Subject: Two Lamp System of Motorcycle Headlamp

Dear Mr. E. T. Driver;

We are now going to carry out engineering design of motorcycle headlamp of two lamp system as illustrated below.

We know well that there is a fact that the motorcycle with two lamp system headlamp has already been on sale in US market.

We would like you to confirm your opinion concerning the legal applicability of the two lamp system of Motorcycle headlamp.

Configuration of Two lamp system Motorcycle headlamp: INSERT GRAPH HERE Longitudinal center plane of Motorcycle

Upper Beam

Lower Bean

Upper Beam Motorcycle headlamp assembly Lower Beam

Motorcycle headlamp units

1. Photometric performance:

1-1) Each headlamp unit has equivalent dia. in dimension and photometric performance to the other and is designed to comply with the photometric requirements of table 1 & 2 of SAE J584 "Motorcycle and Motor Driven Cycle headlamps "specified in FMVSS No. 108, having two filaments (One is for upper beam and the other is for lower beam).

1-2) As for the combined max. value for the upper beam headlamp, the headlamp unit is optically designed to be less than 75,000 cd.

2. Installation arrangement:

Each headlamp unit is symmetrically installed about the longitudinal center line of Motorcycle.

3. Aiming adjustment mechanism:

Each headlamp unit is designed to be adjusted independently in horizontal and vertical directions

4. Others:

This motorcycle headlamp assembly is designed to conform to all of the requirements of FMVSS No. 108 and SAE J584.

Would you please get us your advice concerning the following questions;

Question:

1. Whether the two lamp system of motorcycle headlamp be permitted legally or not.

2. Additional question in case that the two lamp system of motorcycle headlamp be permitted:

Whether the following installation arrangement be permitted or not.

INSERT GRAPH HERE Vertical arrangment

Longitudinal center plane of Motorcycle

Upon your kind review to the above, your prompt reply would be greatly appreciated, and we remain,

Yours very truly,

M. Iwase, Manager Technical Administration Dept.

Koito Manufacturing. Co., Ltd.

Shizuoka Works