Headlight bulb failure

**Blackbird** · 24th February 2004, 19:26

This is (errr….was) a 100W halogen H7 bulb from the dipped beam on my Blackbird. It's an accepted upgrade and is well within the electrical capacity of the bike. Before it failed, it had probably run for about 60 hours from new. I was scrupulous in keeping it clean when I installed it, and made sure that the connector block was pushed home firmly.

This is the first bulb I’ve had fail on the ‘bird so I have nothing to compare it with, but judging by the distortion, it got bloody hot! I don’t actually know when it failed but wonder whether the impact when I arsed off in our driveway at Xmas might have initiated the failure mechanism.

My question is…. is this a normal failure mode which other people have seen, or is it something out of the ordinary?

Cheers

Geoff

**dangerous** · 24th February 2004, 19:42

Is that one of those new 'artic blue' bulbs? cos I was thinking of trying one of them.

**Zed** · 24th February 2004, 20:19

Originally Posted by Blackbird

This is (errr….was) a 100W halogen H7 bulb from the dipped beam on my Blackbird. It's an accepted upgrade and is well within the electrical capacity of the bike. Before it failed, it had probably run for about 60 hours from new. I was scrupulous in keeping it clean when I installed it, and made sure that the connector block was pushed home firmly.

This is the first bulb I’ve had fail on the ‘bird so I have nothing to compare it with, but judging by the distortion, it got bloody hot! I don’t actually know when it failed but wonder whether the impact when I arsed off in our driveway at Xmas might have initiated the failure mechanism.

My question is…. is this a normal failure mode which other people have seen, or is it something out of the ordinary?

Cheers

Geoff

Gidday there,

I used to sell these type of bulbs and there was a reasonable failure rate, some would last longer than others. There are always lemons in the batch. Your spill on your driveway might have initiated the failure?

Also, there are lower wattage bulbs available in a Xenon technology which are recommended if you have trouble with 100+w bulbs.

http://www.hella.co.nz/newprod/xenon_ultra/index.html

Hope it's a help.

Zed

**speedpro** · 24th February 2004, 20:45

Reminds me of one of those old flash bulb things

**mccool** · 24th February 2004, 21:04

The mighty VTR has blown two bulbs in 4 years, both in Palmerston on different Brass Monkey weekends. Cosmic or what? They just had the usual broken filament though, not the major meltdown like yours.

Are you using 100/55w bulbs or have you got high wattage on low beam also? If low beam is 90 or 100 that might increase the tendancy to fry.

Seeya
larry

**Motu** · 24th February 2004, 21:16

Well I dunno,but I think 100watt is illeagal,I'll do some checking tomorrow.That's a good start - what does Honda put in,if they don't say 100w,then you know the answer.

Don't them like that often,but have seen them,often poor quality bulb - just because it says Hella or Bosch on the packet doesn't mean that's what is inside.If it didn't say a German name,then the chances of crap are even more likely.

Another cause is overcharging - you have a Honda,say no more...nudge,nudge,wink,wink.

**Blackbird** · 24th February 2004, 21:44

Thanks for all the feedback guys - will have to do some more checking. Most of the Blackbird guys in the UK run 100 - watters so it's not a widespread problem. I run 100 watts on both main and dip. Might just be a random occurence. With respect to Honda having a lower wattage as a standard fitment, it means nothing. Manufacturers will always err on the conservative side, apart from not wanting to melt the eyballs of oncoming traffic, that is.

It's not an arctic blue - they don't show up the greenery so well. I fitted these for last years' 1000 miles Grand Challenge and there's a lot of greenery in the dark on that ride

Thanks for the link Zed - will follow up.

Geoff

**Blackbird** · 24th February 2004, 21:51

Forgot to answer your other question Zed about arsing off. Of all things, I stalled it trying to get round a car on the steep drive of our bach in Coromandel

I was close to the end of the queue when legs were handed out and would have needed a pair about half a metre longer to hold it up on the camber of the drive. Damage to bike was minimal but damage to ego was nearly terminal as the neighbour and her million visitors saw the whole sorry affair

**Zed** · 25th February 2004, 09:19

Originally Posted by Blackbird

Forgot to answer your other question Zed about arsing off. Of all things, I stalled it trying to get round a car on the steep drive of our bach in Coromandel

I was close to the end of the queue when legs were handed out and would have needed a pair about half a metre longer to hold it up on the camber of the drive. Damage to bike was minimal but damage to ego was nearly terminal as the neighbour and her million visitors saw the whole sorry affair

...it's happened to the best of us!

The ole Blackbird must be a blast!

Zed

**What?** · 25th February 2004, 09:33

Yes, 100W is illegal. Not that that stops me running them, and the VTNZ dorks still give me warrants with them in...

Blackbird, I would say your bulb did fail pursuant to the drop. What has happened (I think) is the gas has leaked out, so filament temperature has gone out of control, but has actually lasted extaordinarily well - most would have burned out well before melting the glass.

**Hitcher** · 25th February 2004, 09:50

Don't forget that W equals Watts which is an energy (heat) unit. Your bulb sits in a confined space, designed by the manufacturer to take a bulb producing about 60W. Increase that by 40% and, unless you can diffuse most of that extra energy, something is going to give. It may be the bulb or it may be any plastic in proximity that decides to melt. Cause and effect.