How bright are Harley Davidson LED headlights?

Recently I was contacted by an aftermarket headlight manufacturer to see if I would like to test out one of their H-D compatible LED headlights. After some deliberation and consideration whether it would even fit my motorcycle, I decided to give it a go and say yes. What did I have to lose? At the very least I wouldn’t like it, it wouldn’t function properly or it would prove to be not as bright as my stock LED headlight.

So this is where my journey began to spiral downwards! Down the rabbit hole I went into the land of confusion when nothing was really as it seemed. Science became my playground and equations were swirling around until I became dizzy with logic that made no sense.

I too wondered how powerful these lights were in comparison to what I already have. They were claiming 40W on high beam and 30W on low beam…but that only relates to how much power is being used to produce the output of light. It doesn’t tell me how bright the light is.

So I decided to dig a little deeper. Ah yes…LUMENS! Whatever that means? There is seemingly a whole area of science dedicated to this, so forgive my simplistic approach and interpretation…you may also want to forgive yourself, if you decide to dig as far as I did too.

As I read through the description it stated that on high beam, the LED produced 4800 lumens and on low beam it was 3000 lumens. After doing a quick comparison of other aftermarket LED headlights, it appeared to strike the middle ground, but some headlights were between 6000 and 8000 lumens on the high beam too. But does that mean they are brighter?

Well as much I could figure, lumens is quite a useless figure when comparing headlights because all it relates to is the light emitted in all directions from the source. However what we want to know is the exact level of light in a forward direction at a given distance…because that’s the direction we will be driving or riding into.

Lumens is also quite a useless figure as it only relates to the light source and not the headlight design. What kind of lens or projectors it has. How much light is shone forward and at what angle…the list is endless. So even though one headlight might claim a higher lumens rating…it actually may be a dimmer light that is shone forward. Go figure!

However as an initial benchmark, I thought I would find out what the lumens rating was of my stock headlight. However this figure is not given anywhere by H-D. The dealerships don’t know! The internet is unusually unhelpful and the company themselves would seemingly just ignore my emails asking for clarification too.

I looked at other H-D LED headlights too. The Daymaker is a popular upgrade. Whether the projector type or the adaptive type! However neither are provided with any figures to sink your teeth into. However the Adaptive comes in at £666 and the Projector at £594, which is a lot of money to spend to speculate whether the lights are considerably brighter.

This brings me back to the aftermarket LED headlights too. We know they should be and are brighter than conventional bulbs but we just don’t know by how much. They are seem to quote different figures and lumens being their favourite too. But what we really want to know is the LUX and the Candela rating. What are those?

Lux is a term that I have been familiar with for many years from the photography world, in that it relates to how much light or what light intensity is actually on a particular surface at a fixed point in space. Therefore if I have a light in the corner of the room pointing directly at my subject, the subject will get more or less of that light hitting their surface depending on the distance away from the light.

So I saw a couple of other LED headlights which gave Lux figures but without distance markers…which again is totally useless. Because if the Lux unit measurement is taken at 3m away, then you will know that the Lux reading at 50m away will be considerably less. It is both the near and far Lux levels that we really want to know and a proper comparison.

However a Lux reading is the amount of total light hitting a subject surface, so you have to factor all ambient light too, so unless there is a standard Lux test in a totally dark room at let’s say 50m for all LED headlights, then really this is impossible to grade also.

The final rating is the Candela, which is basically the amount of light intensity directed in a particular direction. It is this measurement which is most useful as it incorporates both Lux and distance factors. So the result is that the light is measured in comparison to how many candles would be lit to produce a certain amount of light intensity in a particular direction.

This is calculated by Lux multiplied by distance in meters squared. However here is an easy conversion website for you to use> Lux To Candela Converter

The big issue here is that few LED headlight manufacturers quote the Lux and distance and certainly most do not readily quote the Candela. In fact various countries around the world have different limitations on the amount of light and the colour of light that is permitted too, and some don’t seem to have any restriction at all apart from maximum allowable angles.

So…where does this leave us when trying to choose another headlight and one that will be a lot ‘brighter’ for the road ahead? Unfortunately there is no easy answer here and once again it relies upon the buyer doing as much research as possible. Hopefully finding anyone else who has fitted the light you may wish to fit and asking if they believe it is considerably brighter or not and was it worth the expense in the final analysis.

Until there is a global standard test for all headlight ratings and a specified Lux rating is given at let’s say 25m, 50m, 75, 100m which will allow candela ratings to be published, then we are still scrambling in the dark until we fit the new headlight and see if it makes any difference at all. That’s quite a gamble really!

At this stage the only option is to go buy yourself a lux light meter and then compare your headlight light intensity at 25ft which many H-D owners manual give as the datum when setting headlight angles to that of another bike which has the headlight of your choice.

Not exactly very helpful here. The industry doesn’t seem to want us to know proper comparable figures. Harley-Davidson and I wager other motorcycle manufacturers are equally as vague or conservative with their figures too. There isn’t a standard rating that all aftermarket manufacturers publish either and regulatory bodies around the world have different ideas on what should be the maximum and minimum allowable light intensity too.

I wish you well in trying to figure this out. I am just wondering how much brighter this new LED headlight really will be now. Video coming soon no doubt.

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