How do you adjust your headlight?

[OlGeezer]

I know, twist the knob. But is there a target? Does one sit on their bike in the garage pointing their headlight at a measured spot on the garage door? If so, what is the height of that measured spot? If not, other than trial an error, what method do you use?

[dirtrider]

Morning OlGeezer

 

As Shown.

 

[OlGeezer]

Kewl!

The graphic even has the correct RT color!

 

Thanks, DR!

 

 

[Quinn]

I just shine my car's headlights at a wall, pull the bike up next to the car and adjust to same height. So far, no complaints.

 

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[AndyS]

What happens if your car lights are in the wrong place?

[AndyS]

 

 

I use this technique prior to my annual MOT (Ministry of Transport) vehicle test. As soon as I ride out of the test bay, I set the height of the light dependant on the weight of the load I am carrying on my bike and also the conditions that I am riding in. Often I lower it down as far as I can so that I don't annoy other road users. There is normally plenty of light to see safely where I want to travel. If it is country lanes with no traffic, I tend to lift it up to get a tad more 'throw' of light down the road.

 

Andy

[Quinn]

What happens if your car lights are in the wrong place?

 

Well, then I adjust them to the wrong place. Remember the question was how do I adjust my headlight, not how should it be done. I figure the car beam's setting is more stable and using it gets me in the ballpark, which is all I really care about. I also assume that if the car were too high it would get flashed by oncoming more so than the bike.

 

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[AndyS]

Hi Quinn, OlGeezer asked if there was a target, so I don't think pointing it where your car headlights aim is a valid suggestion. This would leave your bikes lighting WAY too low. This is due to most car headlights being mechanically lower. The angle the beam is set at (H-X) will be different (normally less) for your car.

Andy

[Clive Liddell]

Every time I exit a parking garage or similar level area with a nice white wall ahead I check to see where my dipped beam cuts off.

 

If I have all cases temporarily full of luggage or groceries and it is a tad high I just accept it. I like my "normal" riding load to give good forward lighting without irritating oncoming drivers.

 

 

[EricJRW]

Thanks for the pic dirtrider...

 

I think I'm going to go make some marks on my driveway and on my fence (for a quick check every time I get home).

 

Eric

[EricJRW]

OK, so I've been looking at this picture and I realized it does not make sense to me. As drawn, 'X' does not really seem to play a roll in the aiming process*, as it seems like the top of the beam is actually at height 'H', when I think it really should be at height 'H-X'. Also, it seems that the arc of the beam should really be centered on the centerline extending from the bike (this I realize is minor).

 

Am I missing something?

 

MS Paint does not do isometric drawing, but here's my best attempt at how I interpret the aiming process:

 

 

* I guess this could be showing the "before" and my picture might be the "after", but the beam it seems should still be centered.

 

 

[Boffin]

The beam is not an oval, it is mostly flat topped, except the side nearest the kerb is 'kicked up' to light up further down the road without dazzling oncoming drivers. The top of the flat bit is at X, with the 'kick' extending above it.

 

Andy

[EricJRW]

Yeah, the oval is definitely an approximation. When the sun sets tonight I will be able to see what beam my bike actually throws (but I was just thinking about this as I made some marks on my driveway and fence).

 

Eric

[AndyS]

....Am I missing something?

 

No I think you have it, but you are interpreting it differently.

H= the exact height of the bikes headlight.

The instructions are telling you to set the flat part of the aim of the headlight at H - X (which if you have the bike 10 meters from the wall it will be 10cm lower than H.

 

In the picture I have attached it shows the 'kick up' more clearly

 

Does that make sense now?

 

Andy

[Quinn]

I'm still trying to find a 10 meter distant wall in a perfectly flat parking lot so I can adjust the beam one cigarette distance below level. I guess I need to borrow a laser level to do it.

 

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[OlGeezer]

I'm still trying to find a 10 meter distant wall in a perfectly flat parking lot so I can adjust the beam one cigarette distance below level. I guess I need to borrow a laser level to do it.

 

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I'm glad someone else said that. I was getting ready to break out my surveying equipment.

 

Of course, instead of 10 cm in 10 m, you could use 1 cm in 1 m or just use the slope of 1% and any units you want (furlongs, cubits, etc), but that might make it just a little too easy.

 

[AndyS]

Industrial estates?,

Fuel stations, Shopping mall car parks,

Plenty of places, but to be honest the whole thing is not that important becuase as soon as you change a variable, the light aim will change - hense the beam adjuster.

[OlGeezer]

Industrial estates?,

Fuel stations, Shopping mall car parks,

Plenty of places, but to be honest the whole thing is not that important becuase as soon as you change a variable, the light aim will change - hense the beam adjuster.

 

Right, but it's good to get a good starting point.

[EricJRW]

Thanks Andy...

 

I did not get a chance to see my beam against the fence last night. But I guess what you are saying is that I would see a round part and a flat part (all the white in the picture represents the beam). I still contend that logically the round part should be shown as centered, but until I have a chance to actually see what my bike is doing, I won't know. Hopefully tonight.

 

BTW, my driveway is 125' long and pretty flat, especially the last 50'. So my idea is to place some marks on the drive and the fence for a quick check based on loading conditions.

 

Thanks again for the input.

 

Eric

[Boffin]

You do not want the round part centred as this will shine in the eyes of oncoming drivers. You want it to shine down your side of the road and onto the shoulder to show where the road goes and to see any roadside signs or hazards.

 

Andy

[dirtrider]

[EricJRW]

You do not want the round part centred as this will shine in the eyes of oncoming drivers. You want it to shine down your side of the road and onto the shoulder to show where the road goes and to see any roadside signs or hazards.

 

Andy

At first that made sense, but then I started to think depending on that (horizontal) angle (not the vertical dictated by X), the light would shine off the road completely. Of course this may not be case at all, depending on the horizontal angle the length of the beam.

 

Obviously I'm spending way too much time thinking about this, but this is typical of me when I discover something new that I have not given much thought to in the past.

 

I'm definitely taking the bike out after sunset and pay closer attention to this. It still seems the most desirable to have the most light directly in front of the bike, since that's where you are about to drive.

[cris nitro]

Maybe I am a simpleton, but I adjust mine on the road. That's why they have a big black plastic turn thingy on the dash. Just kidding of course, but really, I adjust mine to where it doesn't shine in the cars mirrors in front of me. If my wife is on board, obviously I need to turn the beam down due to the additional loading on the rear of the bike. I like to point my beam as far down the road(up) without pissing off the drivers in front of me. I think everyone is making this more complicated that it needs to be.

 

 

Ride on, hooray for spring!

[EricJRW]

Good point cris! I guess I'm just looking for the optimal starting point while sitting in my driveway.

[OlGeezer]

DR -

 

The "H" includes sag in the suspension, right?

 

I guess i need a helper to measure "H".

 

Is the 10m long enough to have to consider "Great Circle" effects in the "H-x" calculation?

 

Tks.

[EricJRW]

Well color me shocked that the beam pattern, on a wall 10m away, is nearly identical to the original diagram.

 

The one curious thing I found was that at maximum height, i.e. I can't raise the beam anymore, it is nearly exactly aimed per the diagram.

 

I can turn the knob counter-clockwise and lower the beam, but it will not raise any higher than 4 inches below H (which by the way I measured to the approximate height of the bulb).

 

So thanks for everyone's input. I learned a lot about this subject...

 

And thanks to OlGeezer for asking the question!

[OlGeezer]

Well color me shocked that the beam pattern, on a wall 10m away, is nearly identical to the original diagram.

 

The one curious thing I found was that at maximum height, i.e. I can't raise the beam anymore, it is nearly exactly aimed per the diagram.

 

I can turn the knob counter-clockwise and lower the beam, but it will not raise any higher than 4 inches below H (which by the way I measured to the approximate height of the bulb).

 

So thanks for everyone's input. I learned a lot about this subject...

 

And thanks to OlGeezer for asking the question!

 

Maybe you have too much sag in your front shock. How many miles do you have on your front shock? Is your sag more than 30% of suspension travel?

 

FWIW, recently I was told that my lights were blinding my friend in front of me. After the ride, I went home and checked the sag in my rear shock. Too much. I adjusted it and the lowered my head light beam. My suspension feels better as well.

 

Oh, no! Yet another variable!

[EricJRW]

Thanks for that. I will take a look.