1985 KRT 100 headlamp bulb replacement

[pinhead]

What is the best way to get at the headlamp bulb on a full fairing KRT?  I took out my original owners manual and it said to remove the headlight cowl and then headlight assembly.  Trouble is, there is no headlight cowl, its a full fairing bike.  So the instructions BMW gave in their owners manual is of no use to the KRT100.  Also, what's the best headlamp bulb, brightness, longevity, etc to replace with?  Thanks!

[The Mighty Gryphon]

No special tricks that I know of.  Just block out a couple hours and take your time.  Turning the front wheel from side to side should reveal a location that will allow you to get your hand in there.  The hardest part of the job is getting the bulb assembly locked into the back of the headlight and putting the rubber dust cover back on.  A very light coat of liquid soap where the dust cover goes helps it slide on.

I've had good luck with the Sylvania/Osram bulbs from the local auto parts store(Carquest).  Look at the light output and life span on the package.  Higher lumens output means less life.  There is a bulb that sells for about $25 a pair that I use.  To get maximum life, I try to run the high beam during the day and switch to the low beam at night to avoid blinding oncoming drivers. 

I usually get about 15,000 reliable miles out of the Sylvania/Osram bulb on my bikes. On my touring RT, I will proactively change the bulb as part of annual maintenance so I can avoid having to replace the headlight at night on the side of the road someplace in the middle of Wyoming or Nebraska. 

 

[frankenduck]

It's 2021. I run LED headlights in my K bikes.

LED vs factory in the RT/RS headlight:

[pinhead]

No special tricks that I know of.  Just block out a couple hours and take your time.  Turning the front wheel from side to side should reveal a location that will allow you to get your hand in there.  The hardest part of the job is getting the bulb assembly locked into the back of the headlight and putting the rubber dust cover back on.  A very light coat of liquid soap where the dust cover goes helps it slide on.

I've had good luck with the Sylvania/Osram bulbs from the local auto parts store(Carquest).  Look at the light output and life span on the package.  Higher lumens output means less life.  There is a bulb that sells for about $25 a pair that I use.  To get maximum life, I try to run the high beam during the day and switch to the low beam at night to avoid blinding oncoming drivers. 

I usually get about 15,000 reliable miles out of the Sylvania/Osram bulb on my bikes. On my touring RT, I will proactively change the bulb as part of annual maintenance so I can avoid having to replace the headlight at night on the side of the road someplace in the middle of Wyoming or Nebraska.

I get my hand back there but nothing moves.  How do you get bulb loose?  I assume you twist counterclockwise but nothing moves.  ?

[frankenduck]

[frankenduck]

[pinhead]

Thanks!! I took one of the glove boxes off so I could get my big hands back there and it came out pretty easily!  I am going with LED bulb too!

[The Mighty Gryphon]

I'd like to go with an LED bulb.  What are you using?  The ones I've seen have big heat sinks that look like they won't fit in the space behind the headlight in the fairing.

[pinhead]

Well I bought the AUXITO H4 9003 HB2 LED Bulb Hi/Lo Beam White Motorcycle Headlight High Power US on Ebay, hasn't come yet.  I will let you know if it doesn't fit.  It is a bulb made specifically for motorcycles

[Laitch]

Although I won't be buying one of these because my H4 incandescents have lit up moose, bear, woodchucks and joggers sufficiently to avoid thrilling outcomes, I'm looking forward to a review of this bulb, especially after watching this news from the other side of the street.

[frankenduck]

Well I bought the AUXITO H4 9003 HB2 LED Bulb Hi/Lo Beam White Motorcycle Headlight High Power US on Ebay, hasn't come yet.  I will let you know if it doesn't fit.  It is a bulb made specifically for motorcycles

An H4 bulb is an H4 bulb.  The notion that an H4 bulb is specifically made for motorcycles is silly. (It's just a marketing ploy.)

For early Ks that use the locking ring the base of the bulb needs to be 31mm or less in diameter.

[frankenduck]

Although I won't be buying one of these because my H4 incandescents have lit up moose, bear, woodchucks and joggers sufficiently to avoid thrilling outcomes, I'm looking forward to a review of this bulb, especially after watching this news from the other side of the street.

He's correct about the 3/4 sided 360 degree bulbs. They're garbage. But a good LED does not have to be thin as he suggests. The LED bulbs I use work just fine (have good high and low beam patterns with no dark spots) and they aren't thin.

[frankenduck]

Another advantage of using an LED headlight bulb is that they consume less power.  Not to save on energy or anything like that but because all of the headlight power goes through the left combination switch since the factory wiring has no headlight relays.  Eventually the contact sparks from 60/55 watts when you go high/low wear out the contacts in the switch.  For example, the LED bulbs I use are 40W high and 20W low so they cause less wear on the switch contacts.

[beemuker]

He's correct about the 3/4 sided 360 degree bulbs. They're garbage. But a good LED does not have to be thin as he suggests. The LED bulbs I use work just fine (have good high and low beam patterns with no dark spots) and they aren't thin.

so, what are you using?

[The Mighty Gryphon]

so, what are you using?

I think the Duck's selling an LED headlight bulb.  He'll give you a good deal if you buy one from him.

[pinhead]

An H4 bulb is an H4 bulb.  The notion that an H4 bulb is specifically made for motorcycles is silly. (It's just a marketing ploy.)

For early Ks that use the locking ring the base of the bulb needs to be 31mm or less in diameter.

I may be wrong, but my understanding of bulbs made in general for motorcycles, have extra design factors included for with standing vibration and avoiding early failure.  Yes they are identical to any other H4 and give similar light.

[frankenduck]

standing vibration

Non-issue for a K75. 

[Martin]

Vibration what vibration? After resisting going down the LED globe route due to bad reviews for a long long time. I finally bit the bullet after finding some good reviews. I bought a pair of Cougar H4's in December 2020 off Amazon $74.57. https://www.amazon.com.au/Cougar-Motor-H4-LED-Installation/dp/B08VRMG5Q7/ref=sr_1_3? Reasonably easy to fit except the rubber boot had to be deleted. As per Frankenducks  YouTube video they are dual sided and there are more and more turning up with good patterns. I've only ridden a couple of night time trips and they are an improvement over the Austa brand halogen 100/55W halogen. The pattern can be adjusted by rotating the globe and it is fan cooled The pictures show a pretty good pattern however the bike was parked to the left  of the garage door brace.
Regards Martin

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[The Mighty Gryphon]

Martin, how does the pattern look when you are back 5m from the door?  The stock H4 bulbs have a widening pattern onto the shoulder of the road that I don't see in your photos.

I do a lot of riding at night on rural roads and I need a lot of illumination to see the damn deer that are waiting just off the road for the opportunity to jump in front of me.  LED's look like the only way to get the light intensity I want without melting all the plastic bits in the headlight, but the ones I've seen have trouble throwing enough light where it needs to be without a lot of scatter that can piss off approaching drivers.

[Martin]

Gryph it's kind of hard to get 5 metres back from the door as my garage is only 6 metres long. And I can't do it from the front as my driveway slopes down. It might take a couple of days but I'll see what I can come up with.
Regards Martin.

[The Mighty Gryphon]

Thanks, Martin!  Hope you're putting some miles on your bike.

[Martin]

I've been off her for a couple of weeks. Izzy must have taken offence at something and she crash tackled me to the ground. A couple of mates came to the rescue and pulled her off me and managed to reinstate me on her for the ride home. We then went away for a week leaving her in solitary confinement without the car to talk to. She has since apologised and we are planning another ride in a couple of weeks.
Regards Martin.

[Laitch]

I may be wrong, but my understanding of bulbs made in general for motorcycles, have extra design factors included for with standing vibration and avoiding early failure

Motorcycle headlight fixtures are designed to isolate the the bulb from vibration as much as possible and transmit the light effectively. The bulbs within them are the same as auto bulbs.

An H4 bulb is an H4 bulb.  The notion that an H4 bulb is specifically made for motorcycles is silly. (It's just a marketing ploy.)

What makes an H4 bulb a motorcycle H4 bulb is that only one bulb comes in the package. 

[frankenduck]

Motorcycle headlight fixtures are designed to isolate the the bulb from vibration as much as possible and transmit the light effectively. The bulbs within them are the same as auto bulbs.What makes an H4 bulb a motorcycle H4 bulb is that only one bulb comes in the package. 

With respect to vibration - it's not like we're riding HDs with noisy paint-shaker motors.

[pinhead]

With respect to vibration - it's not like we're riding HDs with noisy paint-shaker motors.

Thats quite true.  I modified my headlight assembly on a Yamaha RD350 (lots of vibration).  I installed low wattage halogen lights, standard type not specifically for bikes.  They last only a few times for a ride at night before filament fails. 

True the BMW is as smooth as a car.  But not all motorcycles are.  and when the make a general light bulb they have to cover it for any motorcycle application.