Saturday, December 13, 2014

An LED Headlight Bulb - Take that Lucas!

This is a post which may fit better on my Norton page but the same mod will be done to the Hornet so I am putting it here. I am keeping the Hornet faithful to the original but blending a show bike build Vs a rider. Anything that is not original will be able to convert back to stock. Upgrades to the wiring, lighting and an aluminum tank are a few additional deviations being made.

During the past several years four people I know have been lost to car-motorcycle accidents. It rarely fails that I have to avoid “the car not seeing the motorcycle” every 2-3 years. The last time was when a car turned left in front of my Norton which I almost hit. The LED headlight and taillight (detailed on my Norton page) are attempts to stay alive on my bike. LED’s also have the attraction of drawing less power than standard bulbs. The draw for this bulb is reduced from 5 amps to .5 amps for the headlight and should eliminate the need for the headlight relay I have used in the past to keep power out of switches.

The first bulb I purchased was a “Show Chrome” brand H4 Halogen replacement for $52 USD. It had a hi-low beam capability that I thought was a good idea to have. I purchased it and hooked it up to my system and found I had high or low but not both. I also had to reverse the ground and power wires (due to the positive ground of my bike?). A negative ground system would work fine as I checked the bulb with a power supply and it worked properly using negative ground.  I decided to go ahead with high beam only as my intent was to become more visible to cars and draw less current. My night riding is very minimal. 

LED ready to fit into the Lucas reflector. 

I purchased an automotive receptacle and Lucas bullets so I would not have to cut up my stock wiring harness. The next hurdle was fitting the H4 bulb to the standard shell. I kicked around purchasing an H4 headlight but wanted to use the standard Lucas shell so I could convert back to stock when I take my bikes to local shows. Not wanting to cut up my $52 dollar bulb I purchased clones on ebay, with no low beam, for $10 each – from Hong Kong (this turned out to be a mistake - see the update below) I cut the H4 mounting plates to fit the standard bulb Lucas headlight reflector and made a compression spring to hold it in place.

The original H4 left, my custom cutup center, and stock Lucas on the right. 

The LED fit to the Lucas reflector. 

The LED from the front. It is visible but not too noticeable. 

My custom spring. 

The system works great and the bulb is bright white compared to the yellowish Lucas bulbs. (See the October update below ). This should make me more visible to those offensive four wheelers hell bent on taking me out.  The LED simulates an 80W bulb while the factory was 55W on bright. As noted before the amp draw dropped from 5 to .5. My Lucas wiring and switches will appreciate that. One final benefit is that LED’s don’t mind vibration. A stock headlight bulb lasts about fifteen hundred miles on my BSA. They usually don’t burn out but short the filaments which does nasty things to how the bike runs – backfiring or complete shutdown. I will put some miles on the modification and post how it goes. 

My Norton on the left with its Lucas bulb and the BSA on the right with its new LED. The LED is brighter and has a white light that should be more visable to cars. I think it will be a better night bike too although I may offend people with the lack of low beam.

June 2015 - Update:  While the $52 Show Chrome bulb has held up for 4 hours on the road so far. The Hong Kong knock offs gave up the ghost in the first hour and both fell apart; one on the Norton and one on the BSA. I ordered 2 more of the $52 bulbs. Lesson learned.  I will post an update if the Show Chrome bulb fails as well. One observation is that the LED's run as hot as traditional bulbs. After a half hour drive they are just about too hot to hold on to.

The Hong Kong bulb wasn't up to the challenge of the paint shaker BSA 
(or smoother Norton)

August 2016 Update:  The show chrome bulbs are still going strong. I have recently done significant Lucas Wiring trouble shooting which is detailed on my "1970 BSA Lightning" page. In this foray I have replaced my stock alternator with a high output Lucas unit. The impact on the lights is significant as they are much brighter than with the stock unit. Check out the page for more details. 

October 2016 Update: I learned a $52 lesson about LED bulbs this weekend as I burned the one up on my 1970 BSA. After consulting with the Electrical Engineer at work I learned LED's hit a threshold and fail, unlike incandescence bulbs that are more tolerant of voltage spikes and will keep burning brighter.  I had recently updated my charging system with a high output alternator and new Podtronics unit and went battery free. The battery acts like a resistor and absorbs voltage spikes. Without the battery the LED took a voltage spike and burned out. In line resistors may help with this although I am not sure how to proceed. I will add more information about resistors if  I figure it out. The Norton LED is still working fine after 2 seasons of use. 
Part of the learning process....a scorched LED. Resistors may be added to prevent this in the future. An update will be added following this winter's wiring modifications. 

June 2017 Update: This winter I completely rewired the BSA Lighting. Everything in the system was updated and it was switched to negative ground. I have approximately eight hours on the LED bulb and it has not yet failed.  Ideas for why the previous bulb failed are; the starting capacitor failure proceeding the LED failure damaged the bulb, or the LED bulbs don't like positive ground battery free systems. If the new setup fails I will provide an update. I have not figured out how to wire a resistor into the system although I am not sure I need one at this point.  

Electrical upgrades can be found at:  

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  1. I definitely enjoying every little bit of it I have you bookmarked to check out new stuff you post thanks for sharing.

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  2. Thanks for the comments John. The LED bulbs are great on old britt bikes and I have not had issue with my "battery" systems. I need to work on the "battery free" systems or put a battery back in. I will figure it out this winter and place an update once I do. Thanks again. Randall.

  3. Shouldn't the Podtronic Voltage Regulator limit the voltage and prevent spikes?
    You could add a 13 or 14 volt Zener diode up by the bulb as a backup voltage spike protection, as long as it is higher than the normal running voltage of the Podtronics it should be OK. 5 watt ones are prevalent on ebay and fairly inexpensive; 50 watt (4 amps at 13 volts) ones are somewhat more expensive.
    Or a 4700 mfd capacitor rated at 35-50 volts which is what Lucas used on some systems (RE Interceptor S-II) as a battery eliminator.

    1. It my understanding that LED's are very sensitive to voltage spikes and that a battery will absorb these spikes in many cases. Taking the battery out (when I went battery free) removed the protection from the LED. I have an LED tail light made by "bulbs that last forever" which was not impacted by the spike. It has several resistors on the board. Maybe to protect it? My electronics expertise is limited and I have been researching different approaches. I am looking for something to put in the headlight input power wire that protects all of the bulbs. It would need to handle about 5 amps. The Zener idea sounds like a good one and I will dig into it. I am in the process of rewiring the bike and would like to figure this out soon so I can splice it in place properly. Thanks for your comments John!

  4. Thank you for the excellent info & details. I did basically the same mod with H4 halogen dual beam bulb on my 66 BSA Thunder Bolt. Works great, but thinking about going LED in the future and for my other British bikes. I also fitted my Thunderbolt with a pair of super bright LED white projection strobes (hidden under the headlight) that I wired separately & use as a "visual" horn should I see someone thinking about pulling out in front of me. I can post some photo if anyone is interested? J.O.

    1. Hi J.o.murch....The H4 upgrade sounds like a good solution. I have purchased halogen Lucas replacements in the past but the lead contacts on them did not hold up very long. Your solution sounds like it would. What watt H4s did you use? They have the potential to be quite bright but I don't know if my stock Lucas system would hold up well to higher watt bulbs. I believe my upgraded BSA would although my Norton's system barely runs what I have. How many hours do you on your H4 setup?

      I like the idea of your projection strobes as a visual horn. I generally flash my brights for this purpose but it probably does not have the visibility of your LED's. I would like to see pics of your system. Please let me know if you post them.

      Thanks, Randall.

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