One of the upgrades I made while rebuilding the R100GS after the wreck was to install a pair of High Intensity Discharge (HID) driving lamps. I don’t do a lot of riding at night, but when I do it’s usually out in the boondocks where there’s little traffic and lots of deer. More light makes sense in that situation, and with the recent availability of the HID light systems, and their low current draw, it didn’t take long to justify the purchase. I shopped around a bit before coming across MicaTech who sold both a pencil beam and a wider driving beam lamp. MicaTech is now under new ownership and no longer carries the lamps, but Farklemasters carries the pencil beam. These work so well I decided to use a pair of them on the R1200GS when it came time to upgrade the lighting on it. After you get over the price of the lamps themselves (about $300 each) the biggest challenge is where to mount the ballasts, and how to mount the lamps. The R100GS is no exception, as there’s already a lot going on under the fuel tank, what with dual ignition coils and the factory relays and regulators. As shown above, my solution to the ballast problem was to use the spot formerly occupied by the factory ignition coil, and substitute in its place an aluminum bracket upon which is mounted the two ballasts and a hand full of relays. The bracket picks up three brackets on the main spine of the frame, and uses a short boss to provide a standoff for the lower mounting point (that’s the circular feature in the middle of the photo below).
Headlight modulators are, or can be controversial, with differing viewpoints & arguments for & against. Some find modulators annoying. I believe that is, perhaps not always, folks seeing OTHER folks’ modulators, not their own. Some are concerned about oncoming drivers fixating on one’s modulating headlight & aiming for them, this seems to come from the idea that a motorcyclist tends to ride to wherever they fixate on. Studies have shown that adding lights at the rear (& in some instances the sides) of motorcycles makes them more visible and recognized earlier. For the rear, the lights should be red & as differentiated as possible between Run & Brake. Bright clothing, greenish-yellowish helmets, etc. …all have been shown to reduce accidents. I see no one arguing about ‘fixating’ on THEM.
Whether or not to install a headlight modulator on YOUR bike, is a personal choice; the USA government has not made them mandatory. My comments in this article apply to the USA, as headlight modulators may not be legal in some other Countries.
There ARE reasons that motorcycles are specified, since 1978 in California, & specified in many other States, to automatically, upon ignition turn-on, to power headlights ON, without having to manually turn the headlight(s) on. State law & Federal law are not necessarily the same thing, but, typically, Federal law supersedes. In this instance, always on headlights after a certain year model does apply. There is also an argument about certain cars, such as late models, having constant-on headlights …the argument usually is negative, as motorcyclists want only themselves to have such lights, to differentiate between them and cars. That’s a decent argument, but tends to favor modulators in use during the daytime.
The fairing-equipped Airheads began with the 1977 R100RS. The headlight bucket is basically the same as in the unfaired models (except for later models not having fuses, etc., in the bucket). The bucket is not part of the fairing. On the RS and RT the bucket is located behind the front-most protective glass that is part of a ‘tunnel’ assembly with a large protective rubber molding with an outer glass, etc., whose design is such that it offers a relatively smooth front surface to oncoming wind, etc. The expensive outer glass has some orange lines on it. There is no purpose to those lines (stories abound, all wrong) except to draw the eye away from the quite large front glass. While the orange lines were purposely installed for that stylish effect, the headlight/bucket was quite far inwards from the front of the fairing, and thus the outer fairing tunnel glass needed to be of substantial size to prevent narrowing of the headlight beam. There is no aiming or other purpose to the orange lines.
Don’t do any disassembly of the fairing beyond what is noted below, unless you have a good reason to do so!
1. Fold back, barely (just a small amount), one corner at a time, each corner of the rubberized material surrounding the $$$ glass in the fairing. That will just barely expose a phillips screw at each corner.
Is it just me, or is there something un-American about not being able to turn off the headlight on your motorcycle? Especially on a dual-sport bike that spends a significant amount of time donking along at low speeds off road where the factory alternator can’t keep pace with ignition system and headlight drain. Ironically, there is a solution to this problem in the form of a factory BMW part used on bikes destined for delivery every place but America.
As shown in the photo at left, the BMW part number is 61 31 2 305 232, and the cost is somewhere around $75. That’s a ridiculous price for such a simple device, but when you compare the cost to that charged for an equivalent K-bike switch it’s a screamin’ bargain. Your friendly dealer may have to scratch around a bit in the European versions of his parts catalog to locate it, but larger dealerships should be familiar with where to look as it’s a fairly popular upgrade. Even better, it’s also one of the easiest to install, so let’s get started.
This article was originally written (and since then, expanded/edited numerous times) because someone asked about the left-hand switch of BMW Airhead motorcycles if using higher powered headlight bulbs. He did not understand why the existing stock headlight relay would not automatically eliminate wear on the switchgear. The simplified reason is that the stock headlight relay does not do what many think it does, at least on most, especially later, Airhead models. Variances of his question have come up many times, often on the Airheads LIST, but also on various other forums, and even for other BMW models.
It is important to know that the main purpose of the stock headlight relay FROM 1978 is to turn off the headlight, leaving the dash lights and rear running lamp on, during the time the starter motor is cranking the engine. The relay turns off the headlight during cranking, and that’s all.The stock headlight relay from 1978 also does not do theswitching between high & low beams. NOTE that the high beam flasher (‘passing lamp’) function remains, due to a green wire from the ignition switch, as a separate circuit. The headlight relay may or may not turn off the headlight, during engine cranking, depending on year, model, & country shipped-to. On some Airheads, the high beam flasher button (‘passing lamp’ function) MAY be available with the ignition off. It is a matter of where the green-colored wire goes to. It is easy to move a green wire at the ignition switch, and thereby have the ignition be ON, but the headlight OFF, in the PARK function, but there is more to this, and this is not the point of this article.
Using additional relays to control higher-powered headlamps (stock is 55/60 watt) is a must; although some have gotten away with not doing so for some time. Note that the left bars switch assembly is fairly expensive. It is not designed to handle high-powered headlamps, and it would have been, …perhaps, …better if a relay had been used by BMW to handle all the current flow to the low and high beams. This is not difficult to accomplish, and such as the Eastern Beaver kit does it. With that kit installed (or, your own two relays), the bars light switch(s) would only pass current to the extra relay’s COILS. This means that using accessory relays will reduce wear on the left switchgear even with the stock headlight; and usually will increase light output slightly due to a more direct current path from the battery to the relay. This increases the headlight voltage to closer to battery voltage….another way of saying this is that a more direct power path reduces wire and some switching losses.
Sources for appropriate relays are any auto-parts store. However, www.EasternBeaver.com sells complete plug and play kits for your motorcycle, and they may even still have a version with a modulator if you wanted that.
This is simple and self-evident to most anybody with a soldering iron but here we go….
First a primer on headlamps. Rated at 55 watts, an H4 lowbeam headlamp consumes around 55 watts, I guess, which is something like 4-5 amps. With a 240 watt alternator and with barely any charge below 2500 rpm, goofing around in the city, prior to cranking on a cold morning, or when your electric system is failing, it would be good to be able to switch off the lamp. Moreover, the parking lamp is on all the time and can make-do for a substantial part of the safety and regulatory issues, especially in the daytime. Finally, if you need some lamp action, you can always flick on the highbeam the two habitual ways which are unaffected by this mod.