This subject has been covered on multiple times on this forum, but here's a quick synopsis....

• All H4 replacement LED headlamp bulbs (that I have investigated) have a fan. This is because there is a voltage converter with a power transistor that needs cooling help. The higher the light output the bulb has, the more power must be converted to power the LEDs. Therefore, the more Lumens your bulb has, the more heat is being cast off and therefore the greater your heat issue is going to be.

• An external fan unit can add enough extra length to the rear of the "bulb" to touch the multi-colored electrical connection board inside the /6 and /7 headlamp shells. So the first thing you need to do is make sure the bulb adds as little extra length as possible to the bulb, and will not cause interference (or electrical shorts) with items already inside the headlamp shell.

• There is a class of H4 replacement LED headlamp bulbs that have their fan internal to the reflector. You may think, "Ah, fan inside; no extra length issues !" But these type bulbs do NOT generally have light patterns that are useful on motorcycles. Scooters maybe, but not motorcycles. Also, they can only get away with the confined and much lower volume of the reflector because these bulbs are not as bright. IMHO, due to the poor patterns you shouldn't even consider these type bulbs, even if you are a daytime-only rider. The $15 price may be attractive, but don't do it.

• There are full reflector replacements available for standard 7" headlamps which do not directly fit the 190mm BMW headlamp, but may be an option for some R65 models. Being a single bulb and reflector combined unit, they can use the reflector as a massive heat sink and no cooling fan is required. Besides not being a direct add-on for most of the BMW Airhead models, the price is rather outrageous at $155 to $220. See Truck-Lite model 27270C

All this considered, I've been using the 2500 lumen slip-in Cyron H4 replacement model ABH4K-A6K for 3 years and 30,000 miles. About 99% of my use is on High beam, which is creating the most heat inside a /7 headlamp shell. I've never had a heat issue, even though the headlamp on an RS doesn't get direct air cooling. I've since installed these in /6 and single-sided Airheads with the exact same good results.

Amazon link to Cyron H4 bulb

Hope this helps.

Wobbly. Thank you for the info. I’ll check the forum for other posts. But my concern is about the heat generated and how to get rid of it.

Eric

Check out this plug and play bulb..

stores.advmonster.com/native-h4/

Wobbly. Thank you for the info. I’ll check the forum for other posts. But my concern is about the heat generated and how to get rid of it.

Eric -
Heat is energy that is not going away by itself. Without doing some crazy stuff to your headlamp shell there are very few options...
1. Buy a different headlamp bulb that casts off less heat into the headlamp shell. There are 2 ways to do this: Find a bulb that converts the voltage more efficiently (which is trail and error) and dumps less heat for the same lumen output, or find a bulb with a lower lumen output, which simply makes less heat to dump inside the headlamp shell.
2. Add ventilation holes to your headlamp shell to exchange more ambient air.
3. Add a Headlamp Modulator which only powers the HL bulb a percentage of the time.

Hope this helps.

I did option #4, went back to a bit brighter Halogen H4 bulb. So...if anyone is interested in buying a cyclops LED LIGHT for 1/2 price message me. Less than 4 hours usage. Bought from Bobs BMW

Eric

Wobbly, no disrespect to you and your many contributions to this Forum ..which are much appreciated...per your last recommendation, "Head Light Modulator" Have you been riding with the "Headlight Modulator Guy" behind you for any amount of miles ...I have found it is a most distracting and down right dangerous experience. Your Eye to Brain can't put out the Emergency Mode Move over response...it wears you down.
HATE THE MODULATORS.....That's my opinion, I welcome yours.
15087 Chris

Chris -
There is the LAW and there is ETIQUETTE.

In a free society the Law allows each of us many rights and privileges. Etiquette demands that each person must moderate their personal behavior when exercising any right. The adage, "Your rights stop at the tip of my nose" applies.

And so it is with headlamp modulators. Federal Law allows their use in all 50 states, because it's proved they save lives by making motorcycle riders more visible during daylight hours. Federal Law also dictates that modulators must be able to be turned OFF by the user.

I took a 280 mile ride just yesterday with a local riding group. When I was 3rd or 4th in line, the modulator was turn OFF precisely because did not wish to annoy or distract. On the 30 total miles where I was the group leader or riding solo, the modulator was most definitely turned ON, because I value my life.

That's my opinion, I welcome yours.

I have 2 opinions on this subject. As a rider I have been using headlamp modulators since their introduction in the mid 1970's, and rate them alongside tires and brakes as important motorcycle safety equipment. So much so that I refuse to ride without one. As a moderator I know etiquette requires starting a new thread for off-topic discussions.

Did not mean to blast the "modulators" so strongly. It was a "flash" back to a ride over the Kancamagus Hwy... the leader of this HD pack was up my rear for many miles with that distracting constant blinking till I found a turn out to recover my sense's. Honestly here in New England area they are an anomaly. PEACE!

Start a new thread and we can discuss this. PEACE.