What is your preferred headlight beam angle?

[mamcinty]

Hi,

I'm working on several ebike related projects that I hope to share here soon. One of them is a very nontraditional rear light that also includes a head light in the package. It will be designed to accept input voltages found on a typical ebike but also include an optional standalone pack.

My question is this, what is your preferred beam angle? Do you like more of a spot beam (15), flood beam (45), or something in between (25)?

Matt

 

[Drunkskunk]

A headlight beam on a car is generally centered at 50 meters ahead of the car. That gives you 2 seconds of visibility at 55mph (55mph is ~25m/s).

That's also where I like my Bike headlights, 2 seconds ahead. Depending on the bike that's different distances. For a "U.S. legal" ebike, that would be 18 meters ahead. I think it's 14 meters ahead for an "EU legal". My fastest bike I run at the same distance as a car.

A shaped flood is best, so I can see out to the sides. But it needs to be shaped. If I'm blinding oncoming traffic, I'm causing an unsafe condition.

 

[amberwolf]

^^what he said^^

I use car headlights for their beam shape, usually aimed to give me a couple seconds of reaction time at 20MPH, which is the fastest speed allowed here.

I've tried a lot of other ways of making headlights with a wide beam to light up enough road to "make instant decisions" about where to go and what to avoid, but none of them worked in all of the ways necessary.

Most were probematic in beam shape, sending too much light up either wasting it or potentially blinding others. Others just didn't get enough light back to me to see what I needed to under the various kinds of city lighting conditions I ride in. Some did both poorly.

I used a scooter headlight off an 80's Honda (elite?) and that worked pretty well, but doesnt' have quite the beam shape I wanted.

I tried a car headlight off an old 85 ford LTD, and it worked so well (not perfect but good enough) that I prefer those over anythign else I used so far.

I'd like to try HID projection lights, but haven't found one I could get yet. (I try to recycle things where possible, both for cost and just cuz).

 

[dogman dan]

Ideal is kind of both, a wide angle that's fairly dim, along with a very bright spot in the center that you aim far enough ahead based on your speed.

Since I use two cree flashlights for my night riding, I like to aim one for long distance large object vision, and one low to see that board full of nails or broken bottle.

With both my lights, I get a pattern that greatly resembles the headlights on my car. left aimed a bit lower than the right one.

 

[mamcinty]

Good input.

My current setup, which I've run for like 10 years, is a 4700K 35W Solux MR-16 lamp. I ran two of these on my upright and now one on my trike.

https://www.solux.net/cgi-bin/tlistore/soluxbulbs.html

I would ask people and they often said they thought I was a car or motorcycle. I'm about to evaluate two options that will use either the XM-L2 or the XHP50. I am hoping to offer something in the natural white color temperature range. The problem is, as you guys have stated, the optics are just as important as the emitter. The good news is that there is a lot out there to choose from.

Matt

 

[Eclectic]

I wouldn't think that 2 seconds is enough time. If I remember correctly, reaction time is about 1.5-2 seconds. Then you need a couple more seconds to stop. I would think that 3.5-4 seconds would be more appropriate. At 20mph (~30fps or ~9mps) that would be ~120 feet (36m).

Your headlights should illuminate the road ahead of you for approximately 4 seconds of headway.

http://www.drive-safely.net/driving-at-night/

 

[DrInnovation]

I'm more of a spot like type, My dual -6W cree 6000K headlight has a horizontal angle of about 12degres hot and 20degrees total. With the overlap the hot zone is about 18 degree horizontal pattern and 12 vertical, with sufficent lighting for me to see probably 40 degrees wide and 25 high, i.e. it provides a nice bright region in the middle and softer lights on the sides. I have it mounted so while riding I can adjust it vertically from about 2m in front of me to 100m or more away on flat ground. When riding on trails I aim much closer as there are more obstacles and I am going slower, when on side roads with no streetlights I aim about 25ft ahead and on busy roads I aim at 50-100m because on the busy roads I don't use it as much to see but to be seen. I've had folks comment the double and bright light makes them think its a motorcycle. Keeping the light more of a spot makes it seem bright even though it is only 500 lumens.

 

[Nobuo]

I really like flood beams, I see a more balanced illumination, but however I never pass over 30mph