So, I started a new commute this year that takes me a considerable distance along the W&OD bike path near Washington DC. Now that it is dark, I have noticed that many people cover their headlight as a "courtesy" as they approach an oncoming cyclist. Unfortunately, all my bikes have dynohub driven lighting with the headlights attached fairly low on the front rack, so I can't easily move my hand over to cover the headlight. I could be imagining it, but it seems like the fact that I am not covering my light leads some folks to not only uncover theirs, but also point it directly at me, which I find rather annoying.

So, first of all, I was wondering if others have experienced this, but I also wanted to get an idea of what others tend to do with their lights as they approach other cyclists. I had previously been riding mostly on the street, so I haven't run into this much before. Personally, I think that covering your light while riding on a dark path is not the smartest thing to do, even if it reduces the glare to an oncoming cyclist. You certainly don't turn your car lights off when you are approaching an oncoming car, after all. I am interested to hear others thoughts on the issue.

On a side note, it did occur to me that even if others think I am a complete @ss for not shielding my headlight, there is no way they will ever recognize me when it is light out, so I have that going for me...

If your lights are mounted low, I doubt if it would be much of a problem, but you could always adjust the angle so they don't shine up as much. Almost all of my trip is on streets and late at night, 11th Street NW to Kansas to 3rd Street NW, so blinding other bicyclists isn't much of a concern.

Better to see and be seen, than the alternative. I can't imagine that your light is overly offensive to oncoming cyclists if it is mounted lower on your front fork. Unless it is pointed upwards, there shouldn't be anything to worry about. If you're concerned, try propping the bike upright and ride or walk towards it to get an idea of what others might see as they encounter you on the path. You don't want to point the light too far towards the ground, however, if you are relying on it to avoid obstacles at night.

Just don't be one of those high power nighttime strobe people. I friggin hate that.

Fork-mounted dyno light? Any chance it's not a symmetrical beam? A lot of these aren't. They're shaped beam. If that's the case and it's blinding other riders, yours is aimed too high.

I have Busch and Mueller lights on both of my main bikes, and I think they are somewhat shaped. I have fiddled with the angle a bit to try to keep the beam from hitting other riders directly, but it is hard to tell exactly what they are seeing since the light is only on when the front wheel is turning. I probably just need to get someone to stand outside while I ride past them and tell me how bright the light seems to be.

Busch and Muller. Bingo. You're aimed too high.

Your light is designed for the top of the beam to be aimed at the horizon. There will be spill light above that line so that other people can see you but no part of your main light beam should be going above the horizon.

Mine is battery powered so it was easier to set up the light, but I'd bring your bike and an Allen key to a parking lot. Find a reference point on a wall or parked car that is the same height as your light. Ride towards it. If the top of your beam is above the reference point stop and adjust your light down. You want it just below the reference point.

Busch and Muller lights are designed to provide even illumination of the pavement near and far. To get that effect you need a lot more light on distant pavement. So a shaped beam light like this is extremely bright at the top of its beam. If you're shining that part into peoples' eyes I can see why they'd be upset with you. Most high-powered lights aren't as intense as the top part of a Busch and Muller's beam.

B&M lights are properly engineered bicycle "headlights" that don't need to be shielded like bicycle specific "flashlight", or off road lighting to prevent blinding others, sounds like nothing more than an issue with how they're aimed.

If the headlights are designed to be aimed towards the horizon, then maybe they need to be up higher, on the bars if possible.

+1000 for this. I have to turn my head away

My commute is mainly on the mup, and it's very dark. I understand the urge to be a good citizen and not blind oncoming riders so I aim my lights as best I can to illuminate my path and not them. Everyone out there is in the same boat they need to see for their safety so I don't expect them to shield their lights from me, I just make a point of not looking at them directly.

Unlike the superbly engineered lighting units you're using, the Magichines and led flashlights I've used for years are supposed to produce only annoyance and danger for oncoming riders, pedestrians, drivers and low flying aircraft and I've never had this problem. The problems you're describing must be due to the way your lights are aimed.

You forgot high flying satellites

Some of my rides take me within 10 miles of O'Hare airport, and I'm still waiting for that letter from the FAA saying my lights are interfering with landing aircraft.

All but the worst "flashlights" are marginally acceptable to others when its circle of light isn't up in their line of sight, unfortunately the common sense and courtesy needed to aim them correctly isn't engineered into those "flashlights".

Magicshine claims their road lights are correctly engineered headlights in their advertizements, is that not true?
I'm looking for an affordable back up light that's better than the Cateye "flashlight" I have. Its a terrible light that manages to blind others without providing sufficient light to see by.

I had B&M dyno-driven lights on my Breezer for a couple years and the optics did a nice job directing the light below the horizon-line.

Now I have a flashlight on the handlebars of my new ride, and so I have the opportunity to share the pain with all of the ignorants who blinded me on the bikeway with their poorly directed torches. When I outstretch my hand to block their beams, some have interpreted my posture as a gesture of comaraderie: "Hey, I'm great, how's it going?", as I grit my teeth in disgust.

So I was very disappointed to find that the "Light and Motion 350" torch that I purchased recently has optics as crude and offensive as any, and I was determined to improve them. The solution was to clamp on a shield made from sheet aluminum flashing that creates an optical cut-off for the oncoming traffic. There is still a bit of spill so that I can see a small animal crossing from the other side, but oncoming riders do not see my primary beam. It's not perfect but it works pretty well.

Great suggestion. I will definitely try that approach.

No. Fork mounting works best with these lights. Handlebar mounting can be done but is suboptimal. You get better beam patterns mounted low and it'll silhouette all the rocks and potholes better than if the beam is originating from a position close to your eyes. Avoid shadows and you'll have a smooth ride.

+1. This is a great solution for lighting a bike path. If the route takes the rider on a road, it would be good to supplement the fork-mount B&M with a lower power light on the handlebars or on the rider, strictly for being visible to other vehicles.

If the riders approaching you are acting annoyed, it's probably annoying. You need to adjust the angle.

I disagree. I've tried a low mount on lights and it didn't improve anything. Yes, it silhouetted rocks and potholes...with long shadows that hide what is behind or in the potholes. Every pothole on the road because a black featureless pit that I had to ride around because I couldn't determine if I could ride through it or if I'd end up somewhere in the South Pacific.

Frankly, I don't understand where this low light idea came from nor how it is better. We spend our entire lives living under lights that are over our heads...sometimes 93 million miles...and we don't have problems.

Early vehicle lighting was so weak that being close to the ground was the only effective way to illuminate it.

Reaching to cover a light seems like asking for a crash...

- Andy

Maybe when acetylene lamps were in vogue...although those are pretty bright.

One way to check this is to ride parallel to a wall or railing and look at where your beam hits ahead of you.

Luxos U beam pattern by joshua_putnam, on Flickr