I know this has been discussed before on here but that said, I have just recently purchased a 2006 Suzuki Boulevard S50 to ride ONE UP on and use the SPYDER for two up riding. I have been interested in making the Boulevard to be more visible and had the bike in to a Suzuki Dealer to get a battery tender installed. Had asked about Brake light modulation. His response was quick and to the point. They are illegal and that BMW has been told they cannot sell bikes in the USA with their brake light modulation system installed.

With this information I contacted the Kansas Highway Patrol and asked point blank about headlight and brakelight modulation. I am going to post the responses I got below. I would advise Spyder Owners to add the 3rd brake light but be careful with the brake light modulation. Read below for more information. You will see that the KHP also looked at FEDERAL LAW as well. Happy reading and be-advised. Use good judgement in all things---and if your state is like KANSAS----contact legislators to get things moving to change the law for safety for all riders.

--------------------------------------------------------READ BELOW KHP RESPONSE BRAKE LIGHT MODULATION----------------------------

I have provided the applicable statutes in reference to your inquiry, below. Chapter 8 Article 18 speaks specifically to motorcycles. I recommend you go to the Kansas Legislature link http://www.kslegislature.org/li/b2013_14/statute/ and populate the SECTION NUMBER field with 8-1801 and continue clicking on next to view all the statutes specific to motorcycles, except helmet law which is 8-1598.

I do not see where a flashing /modulating brake lamp is currently allowed under current statute as is the modulating headlamp.

8-1702. Approval or disapproval of equipment by secretary of transportation.

(a) The secretary of transportation is hereby required to approve or disapprove any lighting device or other safety equipment, components or assemblies of a type for which approval is specifically required in this act within a reasonable time after such approval has been requested. Such approvals may be based upon certificates of approval and test reports furnished to the secretary by the American association of motor vehicle administrators.

(b) The secretary of transportation is further authorized to establish the procedure to be followed when request for approval of any lighting device or other safety equipment, component or assembly is submitted under this section.

(c) The secretary of transportation shall maintain and publish lists of all such devices, components or assemblies which have been approved by the secretary or under authority contained in this act.

8-1729. Lights and signals; restrictions; exceptions for certain vehicles including school, church and day care buses.

(c) Flashing lights are prohibited except as authorized or required in K.S.A. 8-1717, 8-1720, 8-1721, 8-1722, 8-1723, 8-1730, 8-1730a and 8-1731, and amendments thereto.

8-1801. Headlamps; modulation systems.

(a) Every motorcycle and every motor-driven cycle shall be equipped with at least one headlamp which shall comply with the requirements and limitations of this article.

(b) Every headlamp upon every motorcycle and motor-driven cycle shall be located at a height of not more than 54 inches nor less than 24 inches to be measured as set forth in subsection (b) of K.S.A. 8-1704, and amendments thereto.

(c) Any headlamp, required by this section, may be wired with a headlamp modulation system provided the headlamp modulation system complies with federal standards established by 49 C.F.R. § 571.108.

8-1804. Stop lamps, turn signals and side lamps.
(a) Every motorcycle and motor-driven cycle shall be equipped with at least one stop lamp meeting the requirements of subsection (a) of K.S.A. 8-1721, and amendments thereto.

(b) Every motorcycle manufactured after January 1, 1973, shall be equipped with electric turn signals meeting the requirements of subsection (b) of K.S.A. 8-1721, and amendments thereto. Motor-driven cycles may, but need not, be equipped with electric turn signals.

(c) In addition to the lamps otherwise permitted by this article, a motorcycle may be equipped with lamps on the sides thereof, visible from the side of the motorcycle but not from the front or rear thereof, which lamps, together with mountings or receptacles, shall be set into depressions or recesses in the body or wheel of the motorcycle and shall not protrude beyond or outside the body or wheel of the motorcycle. The light source may emit only white, amber or red light without glare.

I looked up the federal regulation to further educate us both.

49 CFR 571.108 - Standard No. 108; Lamps, reflective devices, and associated equipment.

S5.5.10The wiring requirements for lighting equipment in use are:

(a) Turn signal lamps, hazard warning signal lamps, and school bus warning lamps shall be wired to flash;

(b) Headlamps and side marker lamps may be wired to flash for signaling purposes;

(c) A motorcycle headlamp may be wired to allow either its upper beam or its lower beam, but not both, to modulate from a higher intensity to a lower intensity in accordance with section S5.6;

(d) All other lamps shall be wired to be steady-burning.

The KHP ended his informative emails with this:


I am a 2003 Harley Davidson Electra Glide Classic rider, myself. I too desire to get back home alive and well after a ride. Give me as much lighting and lighting effect as I can get. I pump my brakes when coming to a stop, as well.
Regarding the hierarchy of law and regulation....States can be more restrictive than the federal government and local jurisdictions can be more restrictive, if not prohibited by state statute than the state. The federal regulations on subject at hand (lighting on vehicles) is the standard from which to begin.