• Welcome to the forum website of the Vincent H.R.D. Owners Club.

    Should you have any questions relating to the Vincent H.R.D. Owners Club, or Vincent H.R.D. motorcycles in general, please contact Graham Smith, Online Forum Webmaster by calling 07977 001 025 or please CLICK HERE.

    You are unrecognised, and therefore, only have VERY restricted access to the many features of this forum website.

    If you have previously registered to use this forum website, you should log in now. CLICK HERE.

    If you have never registered to use this forum website before, please CLICK HERE.

35w Halogen too much?

vintagetour

Forum Website User
Non-VOC Member
I have a 50 w Miller Dynamo and points ignition. I recently replaced my standard 45w bulb with a 35/35w halogen headlight unit. Will a halogen bulb overload my Dynamo?
 

Tnecniv Edipar

Well Known and Active Forum Website User
VOC Member
Halogen Watts are no different to Tungsten Watts , it's the total wattage that is relevant. 35 Watt dip or high , + 5 Watt tail + 21 Watt brake light = 61 Watts . Then there is occasional horn use , but of no practical consequence . As long as you don't sit with the brake light on for long periods when the other lights are on it will be fine.
 

indianken

Well Known and Active Forum Website User
Non-VOC Member
Halogen Watts are no different to Tungsten Watts , it's the total wattage that is relevant. 35 Watt dip or high , + 5 Watt tail + 21 Watt brake light = 61 Watts . Then there is occasional horn use , but of no practical consequence . As long as you don't sit with the brake light on for long periods when the other lights are on it will be fine.

I am a little confused here. 61 Watts plus the Watts necessary for a points ignition to function, is more than the stated output of the 50 watt dynamo.

Depending on the battery reserve, riding too long at night with the lights on seem to look like a long walk home?

What am I missing here?

Ken Smith
(electrically challenged)
 

Tnecniv Edipar

Well Known and Active Forum Website User
VOC Member
Indeed you are missing nothing. The British motorcycle electrical system of that period does sail that close to the wind and is why there is such paranoia about riding a standard , originally equipped Vincent at slow speed at night ! With the system in good condition the headlight and tail light load are no problem , the brake light is only used intermittently so will not normally cause a problem. Points ignition takes about 10 watts or so AVERAGE , and I think the coil ignition machines had a 60 watt Dynamo to cope with this extra load. These days of course no self respecting vehicle electrical designer would even contemplate installing a system running close to 100% capacity at night !!
 

vintagetour

Forum Website User
Non-VOC Member
I have come to accept the fact that my lighting is marginal at best. Any danger from the heat from a halogen bulb. Specs say 500 degree F (probably for a 12v)?
 

Tnecniv Edipar

Well Known and Active Forum Website User
VOC Member
I have never known the heat from a halogen lamp to cause a problem , particularly with real metal reflectors and real glass lenses. One way to ensure that the most lumens possible are extracted from the light is to ensure good earthing from the headlamp unit to the frame. Don't rely on the metal to metal contact through the headstock , install an actual earth wire.
 

timetraveller

Well Known and Active Forum Website User
VOC Member
When people fit our 360 watt alternator kit to twins I recommend that they fit a 130/90 quartz halogen bulb. One has to ensure that the dip switch and wiring are up to it but there have never been any problems with either the reflectors, glass headlight covers etc. 35 watts is not going to cause trouble but note Tnecniv's comments about the earth. I would always suggest a decent new wire from the battery negative to the headlamp shell. :)
 

bmetcalf

Well Known and Active Forum Website User
VOC Member
I had a similar hi-watt bulb in my '77 BMW and the shell got hot enough that I went back to the usual wattage. Your results may vary.
 

peterg

Well Known and Active Forum Website User
Non-VOC Member
Howdy Sir,

Couple of things. Whose point ignition/coil sizes, etc? Small m/c oriented ignitions are very forgiving, stock Indian ignitions will function down to 5.5V albeit on low compression motors which don't squelch the spark. How are you regulating that Miller, mechanically or electronically? 2 charge mechanical reg's can draw over 2amps as they age and the points begin to crust over which in turn contributes to more heat in the genie and less output. Disregarding the vagaries of an ammeter, with a healthy battery (8-10 amps), any fluctuation in brightness of your headlight corresponding to a given rpm change is an indication your running parasitic or at threshold.

Effective grounding already mentioned and automatically addressed if you have Coventry type harness which dedicates a headlight ground wire to the aft fixing point on the UFM which in turn takes the battery ground.

A healthy 6V Miller converted to an electronic regulator like a PODtronic with an LED tailight will easily run a 35W halogen in urban/city settings, though I'll readily admit up front to less burden on my setup by virtue of a BTH. It zeroes this load at only 35mph very overgeared on a 46 tooth and 19inch driven wheel.
 

timetraveller

Well Known and Active Forum Website User
VOC Member
Interesting that Bruce Metcalf's headlamp got hot. Mine is a chromed 7" unit (yes I know!!) and it does not get hot when riding at night which is the only time I use a headlight. Perhaps those who live where it is obligatory or who choose to ride in daylight with their headlamp on and who live where the ambient temperature is in the 20s C not the 10s or less could let us have their experience. Perhaps we need to be aware that we are global users and conditions vary. Feedback chaps?:)
 
Warning! This thread is more than 14yrs ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Top