Author Topic: BMW k75 ( K100 ?) headlight dismantling  (Read 14135 times)

Offline foliver

  • ^ Proficient Motobricker
  • Posts: 194
BMW k75 ( K100 ?) headlight dismantling
« on: March 31, 2022, 07:19:36 AM »
Hello all
I feel my headlight is dim, i've cleaned all contacts with deoxit, the bulb is clean, but i would like to dismantle the unit to clean the chromed interior ( i know it's fragile), how can dismantle the front lens from the chromed back part? Or is sealed for ever?

Thanks all for your advice

Fabian
  • Montevideo, Uruguay
  • Bmw K75C 86

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 11299
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #1 on: March 31, 2022, 10:23:52 AM »
I replace my OEM 60/55 halogen bulbs every two years. It's a characteristic of halogen bulbs to slowly lose their brilliance over time. I ride forested roads and highways at night and I'm satisfied with their performance. Many riders have installed headlight relays. These devices improve OEM halogen bulb brilliance and also preserve headlight switches by lessening the wearing effect of full power running through them, although the halogen bulbs themselves still wear out at the same rate. At the cost of 10USD for two bulbs, I'm ok with the originals.

There are also a few LED bulbs that are effective substitutes for halogens that riders here have reviewed. frankenduck likely posted his recommendation here, as have others.

On my K75, once the chrome ring surrounding the glass lens is removed, six clips (#7 in the diagram) are removed to enable cleaning of the lens. If your headlamp is that style, take a photo of the clips in place before you disassmble. Your moto might have the same setup or it might have been replaced with a sealed beam, all of which would be replaced. You will soon find out.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline jad01

  • Motobrick Curious
  • Posts: 28
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #2 on: March 31, 2022, 10:30:21 AM »
I've had pretty good results cleaning the inside of my MC and car headlights without needing to detach the lens from the body of the light.
1. Pull the headlight off of the bike
2. Remove the lamp (bulb)
3. Pour a little 70% rubbing alcohol into the light (a couple of tablespoons or so) through the opening where the lamp fits
4. Swish it all around
5. Drain it out through the opening where the lamp fits
6. Repeat once and then leave it open to dry before reinstalling the lamp

This has always made a huge improvement on my lights. 112350
Jim
'86 K75C, '84 R100RS, '78 R80/7

Offline The Mighty Gryphon

  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 6843
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #3 on: March 31, 2022, 11:06:45 AM »
I've had pretty good results cleaning the inside of my MC and car headlights without needing to detach the lens from the body of the light.
1. Pull the headlight off of the bike
2. Remove the lamp (bulb)
3. Pour a little 70% rubbing alcohol into the light (a couple of tablespoons or so) through the opening where the lamp fits
4. Swish it all around
5. Drain it out through the opening where the lamp fits
6. Repeat once and then leave it open to dry before reinstalling the lamp

This has always made a huge improvement on my lights.

+1  Whatever you do, DON'T TOUCH the reflector with anything.  You will leave microscopic scratches that will scatter the light, permanently reducing the light output.  A slosh with rubbing alcohol is the only thing gentle enough to not damage the finish of the reflector.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline foliver

  • ^ Proficient Motobricker
  • Posts: 194
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #4 on: March 31, 2022, 11:25:19 AM »
Hi, thanks all for your replies
Confirmed it’s the sealed version..thanks Laitch for the diagram
I’ll follow Jad tip, remembering what Mighty points
I’ll change the bulb, I ‘ve never change it, so I guess after the cleaning,  the lamp change,  and socket cause I’ve an intermittent contact that appears twice), it will punch me es the sun!
  • Montevideo, Uruguay
  • Bmw K75C 86

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 5511
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #5 on: March 31, 2022, 11:52:02 AM »
LED vs. OEM Halogen

Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
Buy parts here.

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 11299
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #6 on: March 31, 2022, 12:07:21 PM »
LED vs. OEM Halogen


It seems to me that in the photo, the halogen light on the right seems to illuminate each of the door panel edges as well or better than the white light on the left; however, it could be that from individual to individual, light receptors in vision structure vary in their response to different colored light. That appearance could also be an artifact of the angle of each headlight.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline foliver

  • ^ Proficient Motobricker
  • Posts: 194
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #7 on: March 31, 2022, 12:19:47 PM »
Are today less direct replacements for halogen ones?
What can be the consumption of led ones?
I’ve seen new halogens that claims 50% more brightness for the same wattage, true?
  • Montevideo, Uruguay
  • Bmw K75C 86

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 5511
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #8 on: March 31, 2022, 01:04:13 PM »
It seems to me that in the photo, the halogen light on the right seems to illuminate each of the door panel edges as well or better than the white light on the left; however, it could be that from individual to individual, light receptors in vision structure vary in their response to different colored light. That appearance could also be an artifact of the angle of each headlight.

It's more due to my camera's exposure and how the camera processes different colors and brightnesses at one exposure level. In real life you can see the lines of the rectangles on my garage door just fine for the LED beam.
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
Buy parts here.

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 5511
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #9 on: March 31, 2022, 01:15:12 PM »
Are today less direct replacements for halogen ones?
What can be the consumption of led ones?
I’ve seen new halogens that claims 50% more brightness for the same wattage, true?

The LED H4s that I use are about 40/20W vs. the 60/55W of the factory halogen bulbs.

Yes, plug-n-play direct repalcements.


I've tried all sort of headlights and the LEDs are by far the best. I used to run 100/90W halogens (with relays and upgraded wiring) but have replaced all of those with LEDs now.

The first few years of H4 LEDs were pretty crappy but by 2020 they started getting much better.  The even make the crappy headlight of the K75S work pretty well.

If your headlight has the locking ring mounting then you need to be sure that the base of the LED is less than 31mm. (Many are not because of the cooling fan on H4 LEDs.)

Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
Buy parts here.

Offline foliver

  • ^ Proficient Motobricker
  • Posts: 194
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #10 on: March 31, 2022, 01:23:32 PM »
Nice explanation, thanks Frankenduck
Any link or name and model you can suggest?

Thanks
  • Montevideo, Uruguay
  • Bmw K75C 86

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 5511
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #11 on: March 31, 2022, 01:30:42 PM »
If you want to run a H4 halogen (some countries with vehicle inspections don't allow LEDs yet) then both the Philips X-treme Vision and the OSRAM Night Breaker Plus are good.
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
Buy parts here.

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 5511
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #12 on: March 31, 2022, 01:35:38 PM »
Nice explanation, thanks Frankenduck
Any link or name and model you can suggest?

Thanks

The ones I bought from Amazon are no longer available but if you find one that looks like my picture above it should work.
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
Buy parts here.
Agree Agree x 1 View List

Offline The Mighty Gryphon

  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 6843
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #13 on: March 31, 2022, 02:15:13 PM »
That photo LED vs Halogen is pretty impressive, especially the cut off on the opposing driver side.  That has been the major fault with all the LED h-4 replacements that I've seen.  Just curious, what bikes were those bulbs in?

Are there any issues with getting that LED lamp into the fairing on an RT.  One of the worst jobs I've ever had on the side of a road in the middle of New Mexico was doing a headlight bulb replacement.

  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 5511
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #14 on: March 31, 2022, 02:38:45 PM »
What bikes were they tested on? No bikes.

They were both RS/RT/LT headlights though.

Here's my high tech testing lab.  They were both run from the same fully charged battery with same length and gauge of wire in order to make it an apples to apples comparison.



Difficulty of replacement on RS/RT/LT bikes? About the same major PITA as usual for RS/RT/LT bikes except a tiny bit more difficult since the plastic "rim" of the LED bulb is a wee bit thicker so you have to push the ring in a little harder.  My K1100LT was a real pain.  On the bright side, since LEDs last "forever" you should only have to do it once at home and not have to deal with it while out touring.
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
Buy parts here.

Offline The Mighty Gryphon

  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 6843
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #15 on: March 31, 2022, 06:49:50 PM »
Cool test rig, explains why the beam is higher on the LED side of the test photo.

Looks like LED's have finally made the big time.  Think I'll have to look for a couple.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 11299
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #16 on: March 31, 2022, 07:06:18 PM »
Looks like LED's have finally made the big time.
frankenduck did the best he could with what he has and it's a baseline for further research. To me though, one bulb just emits a different color light than the other in his trial. What interests me about LEDs is their durability but what I'm seeing here doesn't convince me having one will make my life much different.

German industry has made LED bicycle lights into effect tools for road navigation and they must meet uniform codes of performance. Peter White Cycles created a comparison demonstration that was helpful for me in choosing among different products. This is how White assembled it.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 5511
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #17 on: March 31, 2022, 07:51:56 PM »
frankenduck did the best he could with what he has and it's a baseline for further research. To me though, one bulb just emits a different color light than the other in his trial. What interests me about LEDs is their durability but what I'm seeing here doesn't convince me having one will make my life much different.

German industry has made LED bicycle lights into effect tools for road navigation and they must meet uniform codes of performance. Peter White Cycles created a comparison demonstration that was helpful for me in choosing among different products. This is how White assembled it.

You're right that one picture against a garage is just one data point but I can tell you from experience that it's more than just a different color light.

I've tried LED headlights in all three types of K bike headlights (and my cars where I initially tried LED headlights) and it's an improvement, even over the 100/90 halogens I was running.  The bike where it makes the most difference is the K75S. I don't know if you've ever ridden a K75S at night but that S headlight is just horrible. As in really, really, really BAD! My K75S bikes, now with LEDs, are much better for riding at night. I can actually see what's ahead of me and it's definitely SAFER.

If you're looking for a reason to NOT run LED H4s then technically they're still not legal as replacements for halogens and only for off-road use. That's a non-issue for me though. The early LED headlight bulbs sucked due to scatter and not really being all that bright but they're MUCH better now. Back before 2020 or so you COULD get decent LED H4s but only if you were willing to spend upwards of $80-90 each.

And if you don't want LED then it's worth it (and safer) to instead get a good halogen like one of the ones that I referenced a few posts up. When I bought my K1 (same headlight as RS/RT/LT) a previous owner had installed an Osram H4 and I could tell on my first night ride that it's a quality bulb.

JM02
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
Buy parts here.

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 11299
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #18 on: March 31, 2022, 09:41:28 PM »
I don't know if you've ever ridden a K75S at night but that S headlight is just horrible.
If you're looking for a reason to NOT run LED H4s . . .
. . . if you don't want LED then technically they're still not legal as replacements for halogens and only for off-road use.
 
I need no reasons for not running LEDs but I'm not rejecting them, either. I've only ridden a Standard with an H4 and a Bosch circular lens. Once I aimed the light where I wanted it—I rejected the tape on the garage wall method—and oncoming traffic wasn't signaling that it was blinding, I was good to go. I'll admit it's easier to aim and correct a headlight mounted in the Standard's two-bolt headlight cowl than the fairing setup. Nevertheless, ordinary Osram or Sylvania H4 bulbs are good enough for me; however, as far as LED legality goes, I doubt a motor vehicle inspection here in VT (even as self-righteous as it is) would ever delve into the composition of the headlight bulb as long as its high/low function operated. In CA or MA, all bets are off.  :laughing4-giggles:

Auxiliary LED driving lights have an effective place in the scheme of things, for certain, providing both an increased degree of oncoming conspicuity and specific illumination of the road ahead.  112350
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles
Agree Agree x 1 View List

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 5511
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #19 on: March 31, 2022, 10:05:42 PM »
I'll admit it's easier to aim and correct a headlight mounted in the Standard's two-bolt headlight cowl than the fairing setup.

Having owned dozens of K bikes, the RS/RT/LT fairing mounted setup is MUCH easier to fine tune than the bolt on each side system used by the standard and C bikes. No tools required either.



It also has the three position white lever on the right side that allows a super simple 3 position adjustment to adjust the beam height dependent upon passenger/bag loading.
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
Buy parts here.

Offline foliver

  • ^ Proficient Motobricker
  • Posts: 194
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #20 on: March 31, 2022, 11:40:35 PM »
Having owned dozens of K bikes, the RS/RT/LT fairing mounted setup is MUCH easier to fine tune than the bolt on each side system used by the standard and C bikes. No tools required either.



It also has the three position white lever on the right side that allows a super simple 3 position adjustment to adjust the beam height dependent upon passenger/bag loading.

That really seems more precise and fast design than my k75C bike
  • Montevideo, Uruguay
  • Bmw K75C 86

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 11299
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #21 on: April 01, 2022, 12:57:12 AM »
. . .the RS/RT/LT fairing mounted setup is MUCH easier to fine tune than the bolt on each side system used by the standard and C bikes. No tools required either.
I'll admit that looks pretty simple all laid out there but using a hex wrench hasn't been particularly challenging either.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline milq

  • ^ Proficient Motobricker
  • Posts: 245
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #22 on: April 01, 2022, 12:09:58 PM »
Hello all
I feel my headlight is dim, i've cleaned all contacts with deoxit, the bulb is clean, but i would like to dismantle the unit to clean the chromed interior ( i know it's fragile), how can dismantle the front lens from the chromed back part? Or is sealed for ever?

Thanks all for your advice

Fabian

Fabian, has your bike been upgraded with a relay for the headlight? If not, you might check out Frankenduck's write-up on the matter. It can also benefit the life of your headlight dimmer switch.

http://www.motobrick.com/index.php?topic=268.0
  • Southern IL
  • 1988 K75S

Offline foliver

  • ^ Proficient Motobricker
  • Posts: 194
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #23 on: April 01, 2022, 12:27:24 PM »
Fabian, has your bike been upgraded with a relay for the headlight? If not, you might check out Frankenduck's write-up on the matter. It can also benefit the life of your headlight dimmer switch.

http://www.motobrick.com/index.php?topic=268.0

Uuups, thanks milq! No, it’s all original.
I started to read the link yo provides, seems a good move to do.

Txs!!!

I’ve found an Osram night breaker here, so I’ll use that one to start, and anyway I’ll buy a new socket cause the one on the bike has the plastic melted around one of the pin connectors. May be is the time to add the relay on the move…
  • Montevideo, Uruguay
  • Bmw K75C 86

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 5511
Re: BMW k75 ( K100 ?) headlight dismantling
« Reply #24 on: April 01, 2022, 02:46:23 PM »
If you're replacing the H4 socket then get a ceramic one. I use them on my Ks. They don't melt.





Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
Buy parts here.
Agree Agree x 1 View List

Tags: