HID Headlights

[b1k3rdude]

1. A. No. The measurement is of the breakpoint between low and high beam. The arc was measured to be in the correct position relative to the break point in both low and high beam modes. 
   
   
2. A. Of course there is lateral movement because there is movement. But the 'flapping' referred to is probably twice what you would get from the coiled filament of a standard bulb and in no way could it be enough to affect the alignment.
   
   
3. A. What can I say. The bulbs I photographed had their shrouds in the correct place. Can you show an example of a faulty shroud?
   
   
4. A. I find this surprising given that the arc is producing three times the lumens of a traditional bulb. Of course a larger hole would increase the light exposed but it would also increase the risk of light going where you don't want it and causing dazzle. 
   
   
5. A. have you any evidence of heat damage to the back of the bulbs? I haven't seen any. Given that the solinoid is moving the bulb holder, which is designed to carry a plasma arc, I would not have expected the solinoid temperature to be an issue, but if you have evidence, I am open to correction. 
   
   
6. A. Are we talking about the same bulbs? I haven't encountered any that were 'screwed in'. Water sealing of the headlamp unit is performed by the rubber boot not be the bulb/baseplate assembly. The same boot that is used with standard bulbs. 
   
   
7. A. You are right. I rarely get the promised three to ten times the life of a standard bulb and usually have to settle for two to five times the life.
   
   

1. In this instance you need to measure the center point of the arc at hi and lo beam, otherwise what's the point.
   
2. Try several millimetres - which is enough to complete screw the beam pattern - and this is the case for every Telescopic HID kit I have seen in the flash (that's over 10)
   
3. From my experience, if the inner baffle is smaller than a thumbnail (15mm*15mm) that its too small - I have some old HID bulbs I can use to demonstrate my point.
   
4. The reflector is not "seeing" all of the arc,part of the light is being obscured by the outer baffle.
   
5. The issue is that when the HID bulb is in the hi beam position the solenoid is drawing current. Any solenoid drawing generates heat, and at an educated guess I bet in addition to the HID arc itself its pulling more on hi-beam than a Halogen bulb would be.
   
6. To get a H4 Hi/Lo in a HID kit the bulb has to move in and out - video and this also reminded me of another point, as the bulb moves in and out - on most kist the bulb dosent stay perfectly central to the center axis.
   
7. out of the 10 HID I have used/fitted, on half of them either the bulbs or the ballasts needed replacing in under a year (1000hrs @ 20hrs per week) and some under 6 months. That's far far less than the advertised 3000hrs
   

Some interesting information the use of LEDs in a reflector designed for point source here.  (If you are easily bored, skip the first 22 minutes)

Nice find -

• glad to see the chap in the vid reiterating what I have been saying about hid's.
  
• and regarding the LED bulbs he had, I could straight away they were not going to work because -
  

• They were not genuine CREE LED elements, physically too small and the night time shot confirmed that.
  
• The position of the LED elements were wrong, firing from the side. For any home of hi/lo use,  the LED elements need to be in the same position as a normal tungsten halogen bulb
  
• the outer baffle blocking any use of a hi-beam.
  

The guy was spot on, only worth $9. I have a set of H4 LED that look physically like they would be a direct H4 hi/lo replacement, but because as the LED elements weren't CREE I got a full refund and the seller never ask for them back (proving he/she knew they were shit from the off)

Thanks for the info! I'm still kind of baffled as to why so many bikes with these are dazzleships though.

Its because -

• The position of the arc bulb within the main glass envelope is almost always incorrect, so you get a poorly focused beam causing scatter (light to be reflected where its not supposed to be)
  
• The light output from a HID is just to powerful, from the point of view that the stock reflector was only designed for a 55/60W bulb putting out 900-1000 lumens. So any scatter present from H4 bulb is low enough in light intensity not to cause significant amounts of dazzle. Introduce a HID bulb that puts out 3500+ lumens and that same scatter  is 3.5x+ times brighter so far more noticeable..!!
  
• Then there is the telescopic HID bulbs, most of which are so poorly designed and constructed that there is enough freeplay to allow them to wobble and jiggle around as the bike is in motion, vastly making points 1 & 2 much worse.
  
• And lastly we have the arc itself which isn't actually fixed, its also moves about aswell.  Yes only a few microns but enough that it could also potentially contribute the point 1 & 2.