Light travels in a straight line. Draw a diagram with you on a bike on the side of a road approximately 15 feet from the centerline and about 20 feet from the driver of oncoming car. Draw straight lines for the light from your lights and from the car's lights (car 1). Put in an oncoming car whose driver's side headlamp is only 3 feet from car number 1. Which light is going to be blinding the oncoming driver?

Bonus points: Draw lines from your lamp (and the car's lamp) indicating the beam spread for both vehicles... say from 12 degrees up to 35 degrees. The lines will indicate that some of your light will reach the car but some of their light will reach you. Add in car #2 and see where their lights go.

But now consider how many lumens your light (and the cars) puts out. Those lumens can be expressed as lux or lumens/sq meter based on the area of the target. That target is the base of the cone of light from your lamp. The further away the target, the lower the lux of any light. Your light, 15 feet from the center line and 20 feet from the driver is going to have a very low lux by the time it reaches the driver. The light from car #2 has a much higher lux.

Bottom line, don't worry about blinding oncoming traffic. Chances are they aren't even going to see you. If your lights are too polite, i.e. too low power, the chances of not being seen are even higher.

Tighten up your mount. If this is your mount



I've used a similar mount on heavy lamp heads without issue but the bolt under the lamp has to be tight. I also hang my lamps under the handlebars. If the lamp starts to tip, points the light down rather than up.

I've tightened it to point I'm sure I was close to breaking the plastic. So far the CF paste seems to be working. I'm unimpressed with these mounts. They should be using a worm gear height adjustment at this price point.

Dont get me wrong, I want to be seen. Thats why i use 2 headlights. and want to add 2 more.


On that note, Im already taking 2 difficult classes this semester so I dont need your lesson. There is a guy here that custom builds headlights. I have been about 75 yards away and about 30 yards out of his line of sight and been blinded by him in a highly lit area. I have seen his ads, he runs 2000+lumen lights.

Illustrated using a Dodge Caravan and around 1000 lumens of non-cutoff bike lights:


I see people throwing the word "blinded" and "blinding" around a lot. That word, I do not think it means what they think it means To be blinded means you can't see. To be annoyed by a really bright light that you cannot see past while staring right into it, is a different ball of wax. Look somewhere else, like they taught you in Driver's Education, and your vehicle's 3000 lumens of low-beam will suffice to keep you oriented to your lane. It's not like motorists are going around relying on their night-adapted vision alone.

On the MUP, sure. Worry about your impact, because some of your fellow MUP users are going ninja and are relying on their night-adapted vision, with feeble lights or none at all. I just stay the heck away from the MUP, fortunately I have other options here.

When I started getting numerous comments from pedestrians on the power of my bike lights, I started thinking about my bike light's effects on other road users. Today, I've toned them down by running the headlights on medium, which extended battery run time, and adding refraction lenses. I've even shelved my DiNotte 400 taillight, replacing it with lower power MS taillight. I'm still seen by motorists, but without overpowering their visual senses.

As others have said, aim is very important. I get many more positive comments than negative ones about my lights, and have found that a bright light can get the ninja dog walkers to move to the right side of the MUP when it's dark, but nothing can get them to move to the right side of the path when it's light out.

I've been doing extensive night riding for the last 4 years.

I've come to the conclusion you need about 1500 lumens to do it correctly and safely and to ride full speed down hills. Fortunately, this is not a big deal any longer and there are a lot of lights that will get this for you. The best of the bunch are Lupines, Dinotte has some new offerings this year at lower prices that look to be excellent.

What you really need an excellent taillight. Any of those that use AA or AAA batteries are, IMO, insufficient. You need a min of about 100 lumens out the back to really change driver behavior and be safe. Below that, they pretty much don't see you, or at least don't respect you and give you room. Above 100 lumens (more the better), they will slow down and often drive way wide of you. It's amazing and well worth the price. IMO, the best taillight on the market is the Dinotte 300R that is both self contained and exceptionally bright.

J.

I use a MiNewt 200 ("only" 200 lumens) and a couple of Planet Bike "Super Flash" blinkies on the rear. Although this particular MiNewt is well down the ladder on power compared to the other NiteRider offerings, it is still bright enough to get comments from pedestrians, but not so bright that it's blinding motorists or fellow bicyclists. I guess it's a good compromise. It sure lights up the road for the daily commute

Great video. Thanks.

I'm also wondering how the beam focus affects some of these impressions....

Visibility a mile away? Get real!

You can easily be visible a mile away but you won't throw a beam for a mile.

Even with the brightest lights out there, you won't have to worry about blinding drivers. A car headlight is 1300 lumens and there are two for a total of 2600 lumens. There are only maybe 3 lights out on the market that put out that much light - Lupine Betty at 2600, Exposure has one, and Light and Motion has one (i.e. true lumens out the front).

J.

Quite...um...illuminating Cudos!

Here is a sample of 4000 OTF from two flashlight each is running 3 Cree XML led each. The six LED are direct drive. If aim properly it is not too bad. However there are spillage as tthe houses are shine from the spill. You can see some of it by looking at the white colored house and sidewalk on the right side. Note: My Contour video camera does not show the full effect because it does not take night exposure to good. This video sample is actually under exposed and than what is shown.

https://www.youtube.com/watch?v=rVbsk3wF1v4

I do get some cars from a distant flashing their highbeam back at me sometimes when I run this setup but not as often as I expected. Anything less than this sample such as at about 2000 to 3000 OTF is not a problem.

1 mile visibility is really easy to get. Any of the higher end taillights will do it. My $30 MagicShine will do it. There's a stretch of road about 3/4 mile long and straight, with bends at either end, and I have someone from work mention at least every couple of weeks when it's dark that they saw me about to disappear around the far bend when they just came to the straight stretch. I was bright enough for them to notice from that far away.

I'm actually thinking about getting an entire 2nd set of lights, both front and back, another set of MagicShines since I've been using them for close to 2 years now and the only problem has been the Y adaptor cable frays every few months and needs replacement, but those are $3 - and the new ones are heavier and don't appear to fray at all.

One mile visibility would be highly dependent on the location. A mile out in the country might be possible. But in an urban environment...where, I hazard a guess, most people commute...it would be next to impossible. Far too many light sources to compete against. Plus if you have your lights set up so that they would be visible from a mile away, they would be a problem for other road users...and look at what I think of bicycle lights bothering other road users.

Someone in the electrical forum said he thought a 40 to 60 lux Busch & Muller Lumotec Cyo is probably around 200 lumens. I saw a video where someone was showing the beam on a 400 lumens headlight. I know that's double the brightness but it looked like plenty of light to me so half of it would still be enough in my opinion. So maybe dynamo-powered lights might be enough but not too much to blind someone.

I have two XML T6 flashlights (advertised as 900 lumen, 1x18650 each). Just one on full power seems mighty bright to me.

What I wonder if that because car lights' lenses/reflectors have a much larger surface area than flashlights/bike lights, do they look less annoyingly bright? Is there such a thing as lumen "flux"/lumens per unit of area? I'm no light expert.

Edit: Just saw cyccommute's post on lux

I hold that view myself. For example, a 40-watt fluorescent tube might put out about 3000 lumens, but you can look right at it because the light is coming from a large surface. Condense that output into an aperture the size of a bicycle headlight and yeah, now That's Going To Leave A Mark

I wasn't in a downtown area... I was here...



I was riding in the bike lane as required by state law.


This could have been the view from the motorist's sideview mirror of my approach (but it would have had more cars).

I was passing vehicles on the right as they were tied up by the stop and go nature of the rush hour traffic. It is possible that had I been using a light that was visible in daylight, perhaps the motorist would have seen me approaching when he looked into his side view mirror, and paused for me.

No matter what, it couldn't have hurt to have a headlight on when I was riding.

SO running 9000 lumens as going to be too much then as im thinking 2 pro 3000 for bars one on the head

I was wondering this myself, but if car headlights are approaching 3000 lumens, then I really do not have anything to worry about. The other day at the mec in vancouver we were in the bike light section and a guy was looking for a light to see with. I showed him my light, and all the light and motion urban 500 and 300's were out of stock, but they did have a 350 lumen cygolite. He was interested and went to ask a staff member. The staff member told him the 350 lumen light was too bright, it was meant for trail riding and he would get a ticket riding in the city. We were so choked! And it is not the first time I've seen mec staff members try steer people away from bright lights. In fact, they seem to encourage people to buy the cheapest dimmest lights. I've tried many over the years, and all it means is every year I'd have to go and see what's new. Now led technology has improved enough to give one a fairly bright light without all the cables and battery packs.
I've looked it up and there are not legal restrictions except for Germany that I know of. That is ironic considering where the best brightest bike lights come from...

I mostly ride on a rural highway. At night I bike against ferry traffic and it is really hard to see, especially in the rain. I got the nite rider minewt 600 cordless and while it is bright, it is still not bright enough if I am honest. The light just gets absorbed by oncoming traffic and then I still cannot see very well. I do feel a bit sheepish and tend to point the light down to the road, but then I cannot see the road. My husband says my light is not very bright compared to headlights and should not worry.
So, as far as I am concerned, there is no such thing as too bright. If I ride on a mup or come across a pedestrian on the highway I will dim the light or point it down. I have only gotten positive comments from pedestrians and cyclists. The light will not blind you, just don't stare right into it! Those HID headlights that cars have now are so insanely bright! they are legal without restrictions in Canada, so it is getting really hard to tell what is high beam or not. And if cars and suvs can be light up like Las Vegas, why shouldn't a cyclist be using a high powered light? We have to legally follow the rules of the road as if we were vehicles, so we have to see, and be seen.

Stoopid, perhaps, but if being seen is the number one priority isn't reflective gear just as important? Together with lights, of course. But to me, lights says "see better", and reflective says "seen better". Just a SEK from the darkest of dark north.

Look at an ordinary car. How much reflective gear do your find on one of them? Not much. Why? Because active lighting is more important than passive reflection. Really bright lights let you see and be seen. Wear reflective gear if you want but realize it's only a back up to good active lighting.

I ride with 2 cyo lights. That's a total of 120 lumens. I can see fine. With the beam focus, I see as well as I did with my HID light with a cone pattern. My tail-light is a dyno driven taillight, and a PB superflash. Drivers are able to see me and move over. I ride in a suburban area. When I ride downtown I also throw in a dinotte taillight, run off of 4 AA batteries that throws 120 lumens.

I think some of you guys are mistaking road riding with trail riding. Then again, I'm rarely going faster than 15 mph, so if you ride in the 20+ range, I can see the need for more light.