fietsbob

Anyhoo , I have 3 bikes with German made head and tail lights and dynamo hubs. Busch & Muller designed the reflectors to have a cut off beam pattern.
by having the LED in the top facing downward towards the reflector, not at the bottom of a parabolic reflector like a Flashlight & so many other bike headlights..

I have a battery one too..

Flashing strobe lights are Verboten in Deutschland on bicycles, so they don't. they, the dynamo ones have a light sensor..
In mt B&M Eyc senso T the day running diode is a flat little square, 2 of them . the sensor turns the bright diode on as it gets darker out..


Fortunately I don't have to commute in a big city some do to make & spend the big bucks that are to be found there..







..

rebel1916

How do you convince people to mind their own business.

greatscott

You don't need 1,000 plus lumen strobing light for the front during the day, that's absurd! All I have is a 400 lumen and on strobe I can very easily and quickly see it from a block away. In addition to that, you have more control as to what is happening coming at you from the front and can take precautionary measures if needed.

I do however agree in the rear you need 300 lumens to show up real well, and those cobb type of LED lights do not show up in broad daylight, direct sunlight for some reason washes the cobb lights right out.

During the day I use the Lezyne Hecto Drive 400XL on the front on the bar on strobe; and a NiteRider Omega 300 tail light connected to the saddle bag on flash mode.

Extra credit: At night I put the Lezyne on my helmet with the strobe mode, and add a Phillips Saferide 80 on the bar on steady (well, it only has steady); I then add a NR Sentry Aero 260 on the rear of the helmet on alternating flash (alt flash is the side lights alternate with the rear facing light), and put the NR 300 on steady.

Elbeinlaw

How do you convince people not to be rude on line? The message to which you are referring was about convincing loved ones. If you're not one, then it wasn't about you. I don't think the person who wrote the message was suggesting that they were going to ride through town like Paul Revere shouting "You have to ride with lights!"

Elbeinlaw

"1000 lumen … light"

I'm 100% all in on riding during the day with lights. BUT. If you are using a 1000 lumen light, it doesn't need to be in my eyes as I'm riding toward you. Turn it down toward the ground about 10 yards in front of you bike. That means it won't blind me, but will get you seen. Win/win. (I noticed a few weeks ago on the SCT that many of the riders--all in professional riding gear--had extremely bright lights aimed right at my eyes. F-ing rude, gentlemen. [And they were all, every one, men.])

79pmooney

Daytime visibility - I know this is slightly off topic since it has nothing to do with lighting but: my experience both as a cyclist and driver is that jerseys in bright solid colors are seen. Dark is often not and patterns, even really bright ones, often disappear. I wear solid yellow and orange (and white but my experience is that white is nowhere near as good a lot of the time) jerseys most of the time simply to improve the odds that I get noticed. They are the only thing I have done in 50 years of cycling that has drivers coming up beside me in daytime, rolling down their window and thanking me.

Ben

rebel1916

His loved ones don't want to hear it. Believe me.

Elbeinlaw

I rode this morning through residential streets and avenues on routes that appear on maps in Atlanta as "Bike Routes," though there are not bike lanes. Virtually every one of the commuters (this is 7:30 to 8:30 AM) was using lights. I was very impressed.

njkayaker

If they "always" have this argument, it should be easy for you to find one example to show.

I don't think many people say that's why daytime running lights are safer.

njkayaker

The Germans also ban flashing rear lights too.

njkayaker

This is obvious and irrelevant. If they don't see the lights being on, they aren't seeing the lights off (so, for this case, it's the same either way).

The issue is whether the light increase the rate/likelihood of visibility over not having a light.

Since being distracted tends to be temporary, the farther away something is visible means there's more time to longer than the time being distracted.

njkayaker

Why is it "necessary" to even talk about anything?

The process of trying to convince people ideally makes people better understand about the thing. Isn't that useful?

Strobe -> a flashing light you hate.
Blinking -> a flashing light you think doesn't do anything.

It seems that people are using "strobe" for really-bright flashing lights and "blinking" for kinda weak flashing lights.

njkayaker

Are these used on any bicycle light?

I suspect people are talking about high-powered LED lights when talking about "strobes". Some people might be referring to lower-powered LED lights when talking about "strobes".

genec

I just have not encountered LEDs that bright in daylight... They may exist. I am not saying they don't. And it may be an issue of where, as in shady locations or in the canyons of NYC. Pretty powerful for a bike... Heck, I haven't even seen "strobes" on emergency vehicles that I would consider "blinding" in daylight. But again, they may exist.

njkayaker

No one here is talking about xenon strobe lights.

But it's not clear exactly what they are talking about. Some of them appear to not be quite clear on the difference between daytime and nighttime.

The ambient light matters. So does distance.

I sometimes find the flashing front lights irritating (at night). If you are close, there are lots of LED lights that are blinding.

frizzen

California Vehicle Code ARTICLE 7. Flashing and Colored Lights [25250 - 25282]

25250. Flashing lights are prohibited on vehicles except as otherwise permitted.
...
25268. No person shall display a flashing amber warning light on a
vehicle as permitted by this code except when an unusual traffic hazard exists.

If you consider a bicycle an unusual traffic hazard, then feel free to add as many amber flashing lights as you desire. White flashing lights don't seem legal in CA from what I can tell, but they are tolerated by the police. The eyes are much more sensitive to amber than red and they are far more visible. I always use a flashing amber taillight in addition to a red taillight. Nobody sells them, so they must be illegal in many places. Red flashing lights are very restricted. The code you quote allows them on the back of bicycles, otherwise, only police and fire trucks have red flashing lights. A red/amber combo is very eye catching.

john m flores 

Automobile halogen lamps produce around 1,400 lumens. HID lamps produce around 3,000 lumens. So it's not the outright power of a bicycle headlight that's the problem, it is the beam pattern and setup. Most bicycle lights are simple spotlights with a simple round beam pattern. There are some makes that shape the beam and others that have a hard cutoff but they are in the small minority. My Cygolite Metro Pro has an oval pattern that I try to make sure that I point downward.

I'd argue that a 1,000 lumen bicycle light with a shaped beam that is aimed properly is no less blinding than an automobile.

Regarding blinking, blinking or modulating headlights on motorcycles came into fashion about 10-15 years ago. Anecdotally, they are much more visible. I lead motorcycle tours from time to time and have to keep track of a dozen or more motorcyles in my rear view mirror while I'm riding through traffic. The motorcycles with "modulating" lights are much easier to spot in my mirrors. If everyone had modulating headlights, then it might be chaos, but I'd hazard a guess that fewer than 5% of motorcycles have modulating headlights, so they benefit from being different.

NHTSA did a study about this. Here's part of their abstract:

"...having either LA (low mounted auxiliary) or MHB (Modulated High Beam) lamps on the motorcycle significantly reduced the probability of obtaining a short safety margin (< 3.44 seconds) as compared to the baseline lighting treatment....Eye tracking data indicated that the average duration of participants’ gazes at the motorcycle were significantly longer with the LHA lighting as compared to the baseline condition. These results should be interpreted cautiously in light of differences that were observed between participants who reported using a landmark‐based strategy to judge when it was no longer safe to turn in front of approaching vehicles and participants who used other strategies. Overall the results suggest that enhancing the frontal conspicuity of motorcycles with lighting treatments beyond an illuminated low beam headlamp may be an effective countermeasure for daytime crashes involving right‐of‐way violations."

SOURCE: https://www.nhtsa.gov/sites/nhtsa.do...les/811507.pdf

Personally, I do run blinking headlights in the daytime on roads. I try to make sure that it's pointed downward though. Is it legal in my state? I'm not sure. But I ride through some busy places with lots of parallel parking and I need all the help I can get and am willing to risk a ticket in order to be safe.

Based on the NHTSA study, I may look for fork mounted auxiliary lights to add to my kit.

Lastly, if blinking has no effect on conspicuity, why do automobile turn signals blink?

njkayaker

I wonder if a single static light might be unconsciously ignored as being something like a reflection. If it changes, it looks very different than a reflection. The double lights of a car are pretty unique (it's not likely they will be confused with a reflection).

I suspect one reason flashing rear lights are illegal in Germany is because of the chaos/confusion that would result if there were lots of cyclists with flashing lights.

In the US, cyclists (outside of cities) are rare.

It doesn't seem flashing front or rear lights bother cops. I think the legality is moot.

The NHTSA study seem to show that modulating headlights added the same benefit as low-mounted auxiliary lights. I wonder if having two lights works by making the thing more "odd" looking.

More support for flashing being more conspicuous.

frizzen

Just don't use blue lights. Cops are very protective of their exclusive use of blue lights and that will get you pulled over. No purple either, it looks blue to many colorblind people. I would only use red on the back. Drivers expect red lights to be on the back, you don't want them to think your riding away from them, when you are going towards them.

livedarklions

1400 lumens on a car is the high beam. You are never supposed to have your high beams on where you are likely to encounter other vehicles because it is blinding regardless of how it's aimed. Low beam is more like 700.

The turn signal question is stupid. It's to distinguish them from running lights in the same position. I'll turn the question around on you--why don't brake lights blink?

john m flores 

High beams are not only brighter but they're aimed farther down the road. And even if low beam is only 700 lumens, there are two of them, so they're brighter than a typical single bicycle headlight. The shape of the beam still makes a big difference.

Center high mounted stop lights do blink on when you apply the brakes and it's the change in state from on to off that catches other road users' eye.

RonDigsBikes

Nothing beats having a blinking light on the helmet pushing 700+ lumens. When the cyclist is approaching an intersection, looking left and right will immediately light up any reflective surface. I have caught many cars doing this...and it stops 'em right in their tracks.

livedarklions

Mounting a flashing 700 lumen light right where it's best positioned to hit a driver's eyes directly, what could go wrong?

Again, someone so obsessed with eliminating the probability of an unlikely hit that they don't notice the obvious immediate hazard they're creating.

flangehead

Several days ago I was riding in bright sunlight about 3:00 pm along a city street with a dedicated bike lane. I had on a burnt-orange jersey, bright green helmet and I had both bike-mounted lights on in flashing mode. I approached an intersection in the bike lane at about 18 mph and the traffic light turned green when I was about 200 feet away. I had no motor vehicles ahead or behind me. The intersection had very good sight lines, easily 500 feet in all directions and I'd say a quarter-mile off to my right.

I saw a car approaching the light from my right on the cross street and it did not slow at all. I began braking and slowed; the car passed through the intersection at undiminished speed. The traffic light remained green in my direction and I proceeded to cross the intersection.

Thoughts:

1. I don't know why the driver failed to stop. Unless I see an obvious cause (Corona bottle, cell phone..) I'm inclined to be forgiving about such things. I know I have inadvertently driven through red lights in a car. I was lucky I didn't crash but it shook me up.

2. In all likelihood, had I not braked either a) I would not be writing this reply or b) the car would have crashed either into a curb or a light pole.

3. Clearly, none of the visual practices I have (bright clothing, lane positioning, blinking DRL) were effective in this case. Though I often move into the motor vehicle traffic lane at intersections to improve my conspicuity, I did not do so in this case, probably because I didn't have any parallel-ish threats. Based on the angle of approach of the car and the clear sight lines, it would have made no difference. Blinking or solid DRL? Didn't matter.

This incident illustrates where my head is at. Absolute safety in any vehicle type will never happen. That doesn't mean I can't do things to improve my odds.

The "Swiss cheese model of accident causation" (https://en.wikipedia.org/wiki/Swiss_cheese_model) is what I've been trained with, and I think it applies to any vehicle. However, as a "vulnerable road user" I don't have access to the tons of cheese motorists have. (Note that the 30k+ annual road fatalities in the USA suggests motorists don't have enough cheese either.. but on a bright clear Sunday afternoon a ton of car at 30 mph has more cheese than I do.)

So I'll continue using tools to increase my conspicuity, mirrors to increase my situational awareness, road strategy to leave myself an out, practicing bike handling skills for crash avoidance and helmet/gloves. I'm continuously looking for more cheese slices to put on my sandwich.

So, yeah, I'll continue using DRL and, when there's a teachable moment, I'll encourage others to do so as well.

Context/Notes: Until COVID-19, most of my riding was for commuting and utility on suburban arterials both during the day and at night. Lately, I've been doing more recreational riding and have been using more MUP during daylight. Generally, I use front and back lights during the day except when I'm on MUP, where I turn them off. I run a variety of different lights mounted on the bicycle depending on what I have at hand. I have not finished researching all the source materials identified in the other daylight flashing thread, so I may change my mind, but for now I'm running flashing mode during the day. For bike mount, I only have a Cateye Volt 500 (500 lumen) forward and a Fabric Lumasense V2 red 30/100 lumen to the rear available to me at this time. (I recently found myself without a rear light and I splurged at the LBS for the Fabric. The Lumasense has an accelerometer and it goes solid red 100 lumen when it senses decelleration. Of course I can't see it, but my family members tell me it works. It is pretty pricey, though.) I also have a very small white Blackburn 2'fer mounted on the front of my helmet and a bright red Serfas on the back of my helmet, both of which I can easily turn on or off while riding. I only use them during the day when I feel I'm entering a threatening situation and I want to introduce a change in the visual field.

livedarklions

I really don't get this post, this incident doesn't illustrate the value of anything other than good brakes and braking skills. It certainly does NOT illustrate the value of a blinking DRL, and there's a lot of double-talk in that post to try to get around that. I think what you've actually done is construct an argument whose logic could be used to support the carrying of virtually any portable item while you ride. I could plug in "dayglow lucky rabbit's foot" everywhere you have "blinking DRL" in that post, and it would make just about as much sense.