I recently re-configured the headlight on my tandem. It's now on the left (non-drive side) fork blade.
I'm wondering, though, whether, if you have a headlight on the fork blade, one side is safer than the other.

None of the above.

Headlights don't work well mounted low to the ground. The low angle creates lots of shadows due to surface irregularities. On a gravel road perhaps 1/3 of your light seems to disappear due to thousands of obstructions to the light path. Try your light low on forks off-road, then repeat route with light on handlebar - you'll see a big difference.

Lights mounted on the helmet have a another effect - they create little to no shadow due to the light source being practically in line with your eyes. The lack of shadowing leaves you less capable of resolving distance - your depth perception is diminished. This effect is most apparent on off-pavement routes, where you really need all your depth perception to dodge obstacles.

For most bicycling, lights work best mounted at or near handlebar height.

Agree. Higher is generally better for illuminating the road and path ahead.

If you're going to do it, drive side, so you don't have to worry about which side to put down on the ground, when you have to do so.

I never could get used to wearing a light on my helmet. Mine go on the handlebars.

All of the choices already mentioned make perfect sense if you are running a conventional round beam and want the light to see where you're going. If the function of the light is to be seen by oncoming traffic then I would think that light position would be a lot less critical and a helmet would probably provide more flexibility in catching driver's attention.

Any shaped beam can be mounted lower and still be more effective than a round beam. Personally I believe in redundancy and currently run a shaped beam from the top of each fork leg in the city, and couple that with a helmet mounted spot beam. But the brakes on a road bike make that a little less practical than on something equipped with disks.

For off-road use I'd kinda agree that a bar-mount would give the best overall light if only restricted to one light, but a helmet mount has the benifit of lighting up whatever you're looking at and the combo works best for me. I like as little as possible on the bars.

If you're gonna mount one on the fork, then I'd put it on the side the left side.

I have two CatEye Uno's mounted one to each side of my fork. Within a couple of inches from the QR.

This works for me, usually run the top two in flash mode and up higher on the bars I have two mounts for extra lighting if needed. I put these lights under the stem so they don't interfere with my handlebar bag if I choose to use it.

I've seen a few threads discussing the advantages and disadvantages of mounting a headlight high and low. There seem to be advantages and disadvantages to each position and for different types of riding. I've never ridden off-road at night, so I'm not interested in that. I've had lights mounted on my handlebar, at the fork crown, and mounted on the fork or front rack, but have never tried hub level or helmet mounted lights. It's been a while since I've had a handlebar mounted light, but I'm pretty happy with lights mounted so that they're near the top of the wheel, or a little lower or higher. So I don't want to know at what height to mount a light, but simply whether a light on one or the other fork blade has advantages, and especially whether one side is more likely to be noticed by motorists. I've had the thought that, when stopped at a stop sign, a motorist turning left onto the street where you are stopped is more likely to see a light on the right blade. But perhaps a motorist turning right onto the street where you are is more likely to see a light on your left. Any ideas about that?

I have the original Sturmey-Archer dynohub light mounted on the right-side fork blade of my 1951 Raleigh Clubman, but only because that's how it came from the factory. For visibility to a wider range of drivers, the left side makes more sense (in drive-on-the-right countries, that is).

Hmm , I put my hub dynamo powered LED light on the center line, above the fork.


I got a method to fit a handlebar type light on my low rider hoop,
it's on the right side.. forward of the pannier.
Touring, in high summer, battery lights are OK because there is longer daylight.
So most days the tent is up by Dark..