# HID lights going out under vibration?!



## ktronik (Oct 10, 2005)

Hi,

Just come back from the Mont 24hr MTB race in Australia...

2500 riders, 15000 people... the woodstock of MTB races...

Anyway, @ about 4am the HID's started to turn off on the big bumps...

Yes they were being used all night since 6pm or so & were hot.

Yes the batterys were changed every lap...

And yes the head mounted & the bar mounted turned off @ the same time on the same hit...

Not the best as you tend to be going the fastest when the bumps are the worst!! + the fact that you had to wait to re-strick...

As the team mechanic, I had to change all the lights on the two bikes...all in one hour (the time of one lap)...

I ended up straping 4 of my DIY 3watt LS bike lights on... & through together some batterys to give a 8hrs & 4hrs system on both bikes...while still running 1 amp to all the LEDs...

It worked sweet & really saved the day... err night...

But the real question is, is it normal for hot hid's to go out on big hits???

What other things might cause this??

Any answers would be just great...

Thanks in advance 

Ktronik


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## Archangel (Oct 20, 2005)

Just a quick bump because i'm curious as well.




ktronik said:


> But the real question is, is it normal for hot hid's to go out on big hits???


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## ktronik (Oct 20, 2005)

Hey,

I doubt that they go out under vibration...as rally cars ect have HID's, & they don't go out on big jumps...

I was talking to another person...about the trailtech/moonshine hid's...he said that they had the same problem, but only when HOT...he said that his mate rewired the whole system & has had no prob's since...he said that the wiring is badly crimped...

It seems plausible, but I would have to see the wiring to be convinced...

I guess that's what I will have to do...

thanks for the bump...

Ktronik


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## SilverFox (Oct 20, 2005)

Hello Ktronic,

When HID lighting first became available for bike riders, I read several accounts of them flickering and going out on rough trails. I was looking to see if I saved any of the information on that, but I can't seem to find it.

I seem to remember discussions on rubber shock mounting schemes to reduce the hard shocks, but I can't find information on that either.

Sorry, not much help, but it has been observed before.

Tom


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## pyro (Nov 3, 2005)

yes, it is known that the arc can be "knocked out".
usually not a problem unless a bulb is driven under the designed wattage.

I have a 50w light that goes out when i knock it on the table, but only when dimmed to 25W.


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## Orbit (Nov 4, 2005)

Very intresting. I've not heard of it happening. I'm involved in both extreme offroad and rally racing, i also run 6 HID's on my vehicle. The most trouble i've had is where to mount them in accordance with the rule's of competition.
I've clocked up well over 10,000 hours behind HID's in some of the roughest terrain available in Aus, and never experienced a problem even with 8-10hours of continual illumination with the longest period of running being 12 hours and 25minutes on a trip from Adelaide to Dawrin via Charleville and Longreach. Most of my time has been spent behind 6 lightforce 240mm HID"S, which as i see it are the world best driving lights, driving being the key word.

I've raced and driven behind most of the commercially available HID's ie, narva, cibie, nightstalker, hella, lightforce etc with only minor troubles(ballast water logged), and even butchered a maxabeam and mounted it as a spotlight, without too many drama's.

So if that is anything to go buy, then i don't think it's normal.

Just my two cents.

ORB

edit; p.s. my lights have always run at specified voltages, or been air/oil cooled and run at higher levels. have not had any experience running HID's below specified levels.


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## CLHC (Nov 6, 2005)

pyro said:


> yes, it is known that the arc can be "knocked out".
> usually not a problem unless a bulb is driven under the designed wattage.
> 
> I have a 50w light that goes out when i knock it on the table, but only when dimmed to 25W.



Interesting question and comments. Last week my MagHID [was turned on] slid off from the roof of my car and hit the concrete driveway. Only the bezel is hammajang since it landed head first. Of course it was very upsetting! ! ! Surprised that the UCL didn't break. . .It still works fine and I use it around the house nightly.—I'm not saying that HIDs cannot or will not or haven't gone out under sustained vibration and/or impact!


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## ktronik (Nov 9, 2005)

OK... I see...

The HID's in question has a PWM between the battery & ballast...

CHC, your MAGhid running battery direct to the ballast??

PYRO, any ideas if you are running a dimming circuit??

I would say that cars go direct battery to ballast...am I right ORBIT?


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## Orbit (Nov 9, 2005)

ktronik.....yes....you are right ~bows head in shame~
knew there was a reason i didn't do bikes...lol


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## pyro (Nov 9, 2005)

ktronik said:


> PYRO, any ideas if you are running a dimming circuit??




I use a 50W ballast from www.xenlight.com 
It is only possible to knock out the arc when the power setting was coosen as low as possible.
and then there is some force required, it never went out under use, but then, i do no bike races


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## ktronik (Nov 17, 2005)

Hey,

mini bump...

so far we have dimmed & low battery voltages make it easier for them to knock out...so

Where are all the boffins out there that know everything, wanting to prove us wrong??


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## Nubo (Nov 20, 2005)

I've got a Light&Motion HID bike light and it will flicker a bit on very rough bumps. It doesn't go out, but can best be described as a "pink flash". I wrote them about it and they claimed a small amount of this is "normal", from "stirring up the gases", iirc. Not sure if I buy that, since as many point out, there are plenty of HID applications which appear flicker-free. On the other hand, the 10W HIDs are really pushing the envelope so who knows? They did offer to take the light back for a look if it seemed excessive. Since it's only a brief flash on the roughest of bumps I haven't taken them up on it.


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## Justintoxicated (Nov 20, 2005)

I'm Having Problems with my MR16 Size Trailtech HID's too , But I have not had them operating long enough to actualy take them off any jumps on my ATV 

When my HID's are dropping below specified voltage they do go out (duh) but then they fry something along the way too.


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