Hi Don, I answered you in the Vintage forum, LOL.   

For the rest of the folks info, there is no perfect LED drop in bulb.  There is a video at Ytube Headlight Revolutions that while not directed at BMW motorcycles explains things.  I tried cutting and pasting the site to here but for some reason this site won't let me do it.

I myself currently am running a Cyclops bulb in my RT and was in my RS.  Viewing the beam pattern on my garage door showed this bulb to be pretty close to the stock incandescent bulb pattern but not perfect.

I haven't ridden at night in a long time so wonky beam patterns are not a problem, but if I were to ride again at night or get caught out I would like a good clear pattern of light to see with and not peeve oncoming drivers.  A lot of LED drop in bulbs don't provide this.

If I have to ride at night, I will report my findings as to how well this LED bulb worked.  St.

Thanks for the info Steve. I'm not surprised to hear this but was hoping for a new solution.

I keep my fingers crossed Siebenrock will find someone to make a total LED headlight replacement like the do for the GS models.  St.

Here's 4 things you should know about H4 LED bulbs for the Airhead...

• The specs on these type bulbs are changing so fast that there is not a single part number that lasts over a year. Almost each search will start from zero.

• You are looking for a dual beam bulb with an H4 base. It should be between 5500K and 6000K in light color, and have at least 2500L in Lumen output. Bulbs of this description typically consume about 25W of power.

• Most people report better results with their new LED bulb by prying the glass "globe" away from the silvered reflector and then removing the 3-legged dark gray sub-reflector. The sub-reflector is simply clipped into place. Nothing is destroyed or hurt by its removal, and if you decide you want it back, then re-insertion is simply the reverse.

• This last bit is my personal opinion. I offer it because I think it's valid, but some members here seem convinced the idea is full of BS... I'll give you the information and you can decide for yourself. 

All these bulbs are built from LED chips that are mounted to a circuit board. The circuit board then allows the chip to protrude to the focal point of the parabolic reflector. Obviously the cheapest way to produce such a bulb is to mount 2 chips, one on either side of a single, flat circuit board. The problem is that light comes off of most of these chips in about an 165° arc (out of a full 180°). So that with a 2-sided circuit board, light is emitted only over about a 2x165°, or 330°. In other words, with the cheaper bulbs you MAY achieve less than full 360° illumination, that is to say a "less than favorable" light pattern. OK for cars, but not for motorcycles.

A small minority of H3 LED bulbs use 3 circuit boards which are arranged in a triangle. The same LED chip is mounted to each of the 3 circuit boards. The light patterns from the 3 chips emit light over the same 165° angle, but in this arrangement (3x165°) it's enough to completely fill 360° of the reflector to make a full and complete light pattern. 

I am NOT saying 2-sided construction is always bad. Clearly there are a few really great 2-sided types of LED headlamp bulbs. What I'm saying is that you cannot look at a 2-sided ad's picture and tell if you'll like the light pattern. All I'm telling you is that I always purchase the 3-sided construction bulbs and have always been happy with the light pattern. 

An H4 bulb showing 3-sided construction of the LED circuit board

Good luck !

I recently saw info supporting your 3-sided array rationale as well as the in-headlight mods you describe. Found the bulb copied below which looks like it should plug’n’play. No fan. Mixed reviews, weak high beam mentioned by some.  6k, I think 2500 lumens.  

Do the type you show with the big fan base fit in airhead headlights? I have an ‘84 RS.

 I appreciate your response.

Depending upon the LED replacement, the light elements have to be correctly orientated in the headlight.  I found that with the three element bulbs as well as the two.  So far the handful of LED units I have on hand have had a way to do this by twisting the LED in the mounting bracket.

Despite my best efforts some of the bulbs just would not create a suitable beam pattern. Even the best LED units I have found still don't produce an acceptable pattern.   

Don't be fooled by advertising.   

I don't ride at night and I admit any LED bulb in the daylight is better than the incandescent bulb.

I am waiting for someone to post in some forum the name of a company who makes a LED replacement that works to produce the same light pattern as the incandescent bulb in the BMW headlight.  So far, I have gotten close but no cigar.   

Until then I will continue to warn against replacing the incandescent bulb with an LED if you are going to ride at night. 

LOL, I would also love to have a company that produces a bulb that does not take up so much room in the headlight shell, that is too much to ask I suppose.  St.

I’ve been using the Cyclops LED for several years. I, also, do not ride at night typically.  The few times I have, I’ve thought the light was quite good. The daytime visibility is awesome. My riding buddy noticed the huge difference immediately. I also had an ideal situation with my Hannigan fairing - lots of room and cooling space behind the bulb. 

Posted by: @don-walter

↑

I recently saw info supporting your 3-sided array rationale as well as the in-headlight mods you describe. Found the bulb copied below which looks like it should plug’n’play. No fan. Mixed reviews, weak high beam mentioned by some.  6k, I think 2500 lumens.  

Do the type you show with the big fan base fit in airhead headlights? I have an ‘84 RS.

I appreciate your response.

 

1.    4.

 

► The type bulb with the fan did fit comfortably into both the double-sided and single-sided headlamp buckets. In some installations you had to groom some of the wiring away from the center, but this was a 30-second brush job, not a time consuming wire re-routing problem. 

► The photo in question was downloaded 4 or 5 years ago to use when the question of LED bulbs comes up, which is fairly often. However, the efficiency of the miniature power source seems to have gotten a lot better over the last several years. In your current shopping, I believe you will be hard pressed to find a bulb offering that uses the fan. 

► I note that in diagram #4 which you presented, that the newer H4 LED bulbs are the exact same size as the halogen bulbs they replace. So you should experience zero issues with installation, as was sometimes present with the older design.

► Again, I'm not saying ALL bulbs using the 3-sided design are "perfect", simply that it's a better design concept. You may need to buy 2 or 3 different ones (and return the others) before hitting on a suitable bulb.

► Even if you NEVER ride at night, there are multiple benefits to be gained by converting your Airhead to H4 LED for daytime only riding (using even an LED bulb with a "terrible light pattern")....

 • The headlamp will be brighter and more noticeable for on-coming traffic, making daytime riding safer.

 • Since an LED bulb uses 1/3 less current, alternator and rectifier loads will be reduced resulting in more reserve electrical power and longer life for those 2 components.

Hope this helps.

Posted by: @14724

↑

I am waiting for someone to post in some forum the name of a company who makes a LED replacement that works to produce the same light pattern as the incandescent bulb in the BMW headlight.  So far, I have gotten close but no cigar.   

You will be waiting a LONG time, my friend. The standard glowing element of a halogen H4 bulb emits light in an evenly dispersed, full 360° pattern. Since current H4 LED fabrication is dependent upon discrete LED chips mounted to a flat substrate, their light pattern is and always will be (at best) a patchwork of segmented light sources. End results will be based on the physics of the component being used and the accuracy of manufacture. 

Consider that last part. While they are capable of physically positioning the LED chip within several thousandths of an inch on each substrate, that is physical positioning.... which is not necessarily the same as positioning of the LIGHT. Thus even within 5 "identical" LED bulbs made in the same factory on the same day, it's entirely conceivable that there could be variations in light patterns.

There are 2 sides to every coin. 

I don't ride at night and my main reason for considering LED is to spare power for my 48W Warm'n'Safe heated shirt and (less often) Gerbing Vanguard heated gloves during Spring & Fall riding. My OEM alternator seems to handle these ok >3k rpm but at lower rpm's they definitely discharge the battery based on volt meter display. An LED headlight bulb should free up another ~25W or so. The only other non-OEM e-consumers are my iPhone. I'll eventually get upgraded alternator components.

Here's another bulb I'm considering. Other than the color of the frame it looks identical to the one I posted earlier but claims to have considerably more lumens, 4500 vs 2500, but I don't believe everything I read. Probably the same bulb from the same shop in China.

https://www.amazon.com/Ruiandsion-Motorcycle-Headlight-Replacement-Non-polarity/dp/B0B1Q424C1?th=1

You will be waiting a LONG time, my friend.

I KNOW why LED bulbs don't work in the BMW reflectors.  I guess I should have added LOL, to my comment about waiting for a drop in LED bulb to be made.  That was not a serious remark.

My first post I explained I tried to add a website address for a detailed explanation but could not cut and paste the address into the first reply I wrote.

The only way we will get a properly functioning LED headlight for the majority of airheads is if a company like Siebenrock can source a complete unit, bulb, reflector and glass as they have made available for the GS bikes.  

Until then, as I wrote, I don't think replacing an incandescent bulb with a LED unit is a good idea if you are going to do any night riding.

Daytime, who cares, what the beam pattern is, LOL, the more annoying the quicker it gets attention perhaps.  St.

LOL, Don, I get a kick out of the tons of "drop in" LED bulbs that promise the sun the moon and the stars for performance then fail so badly to actually provide it.   I have four or five bulbs in my tool box that promised flat white light pattern at night and instead produced a blinding blob.   LOL, I was lucky I took the time to install and then check the beam pattern on my garage door first rather than just proceeding to go riding at night.   A couple of the LED bulbs would likely get me run off the road for blinding oncoming cars.

Yep I am considerate enough to check night performance even though I don't ride at night because one day I may have to ride at night and I would like to see, that is me, LOL.

For daytime even the worst bulbs performed better than the stock incandescent bulb did.   So if I am forced to admit it, I consider switching a good thing, as long as the shortcomings are known.  St.

Just stumbled across this LED replacement headlight (not just a bulb) on the Motorrad Elektrik website. That website doesn't post reviews and I've not seen any comments on it elsewhere. Kinda alien looking. No manufacturer reference. Has anyone found any reviews or know of a rider who has tried one?

Link:  http://motoelekt.com/lighting.htm

"Available for /6 and later models, in black or chrome." $174.95 /5 $154.95

"This replacement headlight is as easy as changing a stock, original reflector. The original spring clips are used to hold things together, and the nylon adapter ring secures the new lens/reflector unit.

This is a DOT/SAE approved lamp, legal in all jurisdictions. The slightly smaller diameter is made up by the adapter ring holding the new light and fitting precisely into the original chrome retaining ring.

The difference in lighting is nothing short of astounding, especially if you've grown accustomed to the feeble yellow light from a dingy, clouded reflector and lens.

The prices of new reflectors and lenses are an eye-watering $379.00, so this conversion will allow modern, safe lighting without breaking the bank."

[Mods added the missing Link to the item being discussed.]

Well Don, I haven't been on ME's website in a long time.  LOL, haven't needed anything.  This system could well be what we need to give a proper light at night.  A designed whole unit.  Not a cobble job. Rick at ME is very good with customer relations, I trust him to sell proper products.

With the cost of some of the drop in bulbs being pretty high, it might be worth a try.  

If you buy it let us know how it works out.  LOL, I am afraid I am too cheap at this stage to buy it myself.  IF I rode more at night, I really would seriously look into this unit.  Good luck, St.