Interpretation ID: aiam3902
Manager
Automotive Lighting
Engineering Control Dept.
Stanley Electric Co.
Ltd.
2-9-13
Nakameguro
Meguro-ku
Tokyo 153
Japan;
Dear Mr. Chikada: This is in reply to your letter of January 18, 1985, to Mr. Vinson o this office asking for three interpretations of Motor Vehicle Safety Standard No. 108 with respect to motorcycle lighting.; Your first question is about the location of rear turn signals. Tabl IV of Standard No. 108 requires that rear turn signal lamps on motorcycles have a minimum horizontal separation distance 'centerline to centerline' of 9 inches. You have asked whether this may be interpreted as filament center to filament center., The answer is no. The phrase means the distance from the geometric center of one lamp to the geometric center of the other.; Your second questions concerns the permissibility of an arrangement o lamps on the rear of a motorcycle. There would be a two-compartment combination stop/tail lamp on the vehicle centerline with separate combination lamps below it on either side of the centerline. The distance between filament centers of the separate lamps would be a maximum 16 inches, and there would be the same distance between the filament centers of each separate lamp and the compartment above it belonging to the two- compartment lamp. You have asked whether this is permissible if the minimum design candlepower complies with requirements for three lighted sections in SAE J585e and SAE J586c, and the effective projected luminous lens area of each compartment or lamp is at least 3 1/2 square inches. This arrangement, though unusual, appears to be acceptable. SAE Standard J586c *Stop Lamps* and SAE J585e *Tail Lamps* state that if multiple compartment or multiple lamps are used, and the distance between filament centers does not exceed 16 inches for three compartment or lamp arrangements, the combination of the compartments or lamps must be used to meet the photometric requirements for the corresponding number of lighted sections. Your design has four lighted sections, where as the SAE Tables provide values for only three. In our opinion, your design would be acceptable provided that each of the four compartments meets the minimum value specified for test points in a section when there are three lighted sections.; Your final question concerns a combination stop/taillamp of fou sections, two each on either side of the vertical centerline. Though no distance is given for the filament centers, they appear to be closer than 16 inches. You have asked if this design is permissible provided it meets the requirements for three lighted sections, and the effective projected luminous lens area of each compartment is not less than 3 1/2 square inches. The answer is yes, this is acceptable provided that each of the four compartments meets the minimum value specified for test points in a section when there are three lighted sections.; Sincerely, Frank Berndt, Chief Counsel