When I got my L2D's I couldn't wait to try one, so I turned it on in my cubicle, which is right by a window with plenty of outside and flourescent light, and 6 foot tall cubicles, with the top 2 feet being translucent. I am in a section of the building that when people come by, even on cloudy days they comment about how bright it is. When I hit the strobe mode in Turbo, the person in the next cubicle thought there was some sort of emergency.

Last night, I went to drop off a package at a neighbor's house last night (it was delivered to me by mistake), so I brought my Fenix for a first night time look. In medium it seems to provide as much light as I will need for cycling. In fact, I think the low level would be fine for most of my riding. I will have two, one for my bar, and one for my helmet, but I am reconsidering my thought of getting a second one for the bar. I have no desire to be seen from space, although pointed slightly differently, I envision a better hot spot.

There are always exceptions, but I think that most people who think they need more than the high level (non-turbo) of an L2D simply need to take a deep breath and realize that anything extra is probably doing more to blind oncoming traffic than lighting the road usefully. I light up more road (especially distance, although a narrower beam) with the L2D than with my car headlights.

More is not always better, and with lights this is especially true because we have to coexist with others. Have you looked into the light yourself? At night? For those of you who have flashed it at drivers, you have probably blinded the driver, placing yourself or others at greater risk. I flashed the thing in my eyes, during the day when my eyes were accustomed to light and I saw spots for several minutes.

It is nice to see (and be seen) while riding, but for most of us, I think we should consider whether having things too bright is actually counter-productive. It seems reasonable that if you light the road too well, then you actually make it harder to see anything outside of the light's beam... For goodness sake, I can see the light from my L2D hit the road during a cloudy day!!!

I am a person who while driving or riding really loves the too brief period after sunset when the glaring sun goes down and it is still bright enough to see, so perhaps this is why I don't see the need to mount a piece of the sun on my bike for light.

I am sure there are many who will disagree with me, so please share... Please note the phrasing of this question is sarcastic, but it only stretches the truth slightly... Why do you think things have to be as bright as high noon to be safe while riding at night?

It depends on how much night riding experience you have, how fast you ride, the condition of the roads and your familiarity with them, whether there is a moon, how good your night vision is, and whether you ride trails or mountain bikes.

I do agree with you. A Fenix on the bar and one on the helmet will meet the needs for the vast majority of cyclists. With two the high setting is probably adequate, but I would go turbo for rides of 2 hours or less or if you are out in the country and seeing dogs or other animals is an issue. Or run one on turbo and one on high so you would be certain to have enough light to get home.

I think running it on medium would be inadequate for most cyclists. You might want to try it first and then comment further. The Fenix on medium is still better than my L&M Vega on the highest setting.

Blah blah blah. If you are content with riding with low power lights so be it. Let others use what they want. "low power" meaning, low power to me.

Just because a light is bright, doesn't mean it has to be positioned in a way to blind other road users. Think about it. An L2d would be the minimum i'd ride around here with. Just because a light is bright enough for driving doesn't mean it's bright enough for riding.

I speak for myself when I say i'm well aware of how un-courteous and distractring bright lights are that are not aimed properly. See this thread of mine for example: https://www.bikeforums.net/electronics-lighting-gadgets/378867-biasing-200l.html

What I tell people is that it is far more important to have a light that works, than to worry about how bright it is. IMO, around 80ish lumens is enough to see in the dark at a decent speed. Anything less is stilly generally fine for letting others see you. Really, past a certain point, you get rapidly diminishing returns for your money. In addition to possibly blinding others, the amount of light needed depends on the speed one's riding at, as well as the presence or absence of ambient lighting.

You fenix is plenty bright enough for anything, as long as that rock on the road is in the small spot of light it throws. That spot is so bright your eyes adjust to it and have trouble seeing whats outside it.

If you want to ride for several hours on unfamiliar rural roads 200 to 400lm from a light that actually lights up your lane smoothly and evenly for 20-30m (thats 3 to 5 seconds at 25kph). 10-20w of halogen or 2.5-5w of led. You do kinda lose that "omg is something going to appear suddenly out of nowhere" thrill though.
If its wet 400lm minimum.

Off road, more.

I find my L&M Vega at 85 lumens to be barely adequate riding in a group of cyclists with much better lighting and would never consider riding solo with this pitiful amount of light. Others would disagree. I have had some younger riders tell me they use the Vega for mountain biking, although I don't see how.

I am with znomit, 200 to 400 lumens is closer to what most cyclists need. By most cyclists I am thinking of riding 16-17 at night in cold winter air. If you are riding solo at 20+mph and riding full speed down hills, then 600 lumens or more would be needed imho.

I have said this many times before; I run a 20w mr16 bulb. One of the best halogens I can get (osram IRC). Its a 12deg spot and I pump around 13v (due to craptastic batteries). And I don't think it is enough. (700lm, 35lm per watt??)

Also With my 2.3Ah batt it only lasts an hour.

I would say two 50w IRC flood lights at 17v would be good. But to power that you need a large batt pack or two.

At 17v I think it draws 7 amps ( maybe more).

Thats a strain on switches wiring and the batt.

And you WILL 'blind' people who glance at you lights. Mainly because they have a round reflector, and no horz. cut off.

What? You mean to say that driving at 70mph in a car requires LESS light then riding a bike at 20? Did you even read what you wrote?

As an ex-Vega owner (the light fell off and was run over) I see what you're talking about. The Vega gives a bright spot but very little light around it. As someone who prefers a flood, my current modded Ellipsoid has roughly the same lumens but lights up the road better due to the more diffuse beam.

No, I would not go MTBing with my setup. It's OK for roads, and that's it. I'd gladly take 200 lumens if it were available, but it isn't.

When it comes to considering how much light you need think about this: a few years ago I was in a car at night with a working set of headlights. Another car coming in the opposite direction turned in front of me and I hit him. It wasn't serious, but I asked him why he turned and he said he didn't see me. I guess two 35+ watt headlights wasn't enough!

So when it comes to biking at night, I want to reduce any chance of not being seen so I have some super-duper bright light. While commuting, I see several other bikers, most sans lights and if I can't see them on the MUT when we're both going 15mph, there's no way a car is going to spot them in enough time. The cheap lights help a bit, but you almost have to look for them; they're about as bright as the light reflected off a reflector. It's not until ~500 lumens or so (such as an HID) does the other bike headed my way get my attention.
I've tried several lights over the years and again, 800 lumens doens't seem to make much of a difference driving in the city and suburbs than 500 lumens. Cars don't pull out in front of me, pull into my lane or turn in front me as nearly as much as when I was using a 15 watt halogen. This was confirmed to me again the other day when I forgot to charge my LED light and it went from 10 watts to the power saving mode of 1 watt and I suddenly needed to take a more defensive mode driving as cars just didn't see me.

To each his own but consider that we little monkeys are diurnal and not nocturnal. We can see at night but we really suck at it compared to the things that used to eat us before we found out about rubbing sticks together Also consider that most everywhere we little monkeys go, we are still afraid of those things that used to eat us, so we put up light everywhere and as much of it as we possibly can. In other words, we have banished true darkness. The problem with that is that you now have to compete with all of that light to get noticed so that the big iron machines that want to eat us little cyclists now won't. A low intensity light is a knife in a gunfight...not a good thing

The big metal machines that want to eat us cyclists don't care if they blind us, so why are you worried about blinding them? Do you honestly think that the average car driver worries about blinding someone on a bike? Heck, most of them have to be reminded to turn down their lights for other big metal machines. Plus, the last time I checked, any bicycle light can be aimed, that's what the reflector is for. If we ran around with 100 W round lamp bulbs on our heads, then blinding traffic might be an issue but with an reflector you not only gather the light, you also can point it where you want it.

I do try to coexist but that doesn't mean I'm going to disarm to do it. First, how close where you to your light when you looked in it? Arms length? Try looking at it from 10, 20, 30, 40 etc feet. The intensity falls off very quickly. That's part of the reason I use very intense lights. Mine are much more intense at 40 feet than yours is. The big metal machines aren't going to mistake me for anything other than a big metal machine

If I flash my helmet light in someone's eyes, I have good reason to do so. I don't do it capriciously nor maliciously. I do it because the driver has not noticed me and is about to do something that will endanger me. And, because the intensity of the beam is lower the further away you get, I doubt that they are blinded. I have looked into my beams at a few feet away and I could still see. Yes, there were small blue spots but I get that from cars.

Using a light at night automatically decreases your night vision, even a relatively low intensity one like your L2D. Add to that the overall lighting you find in any urban area and your night vision is completely shot. But to get good night vision requires about 30 minutes of no light. Most of us take out of work and head home right away. Since we are generally leaving a lighted area, our night vision isn't that good anyway. You might be getting good night vision by the time you get home but unless you are willing to stand in a dark closet...outside...in the cold...for 30 minutes, you'll need your lights anyway.

Astronomy people don't allow any kind of light when they are observing because it decreases their night vision. Some of them will grudgingly allow a very low intensity red light but you'd better keep it very small and use it infrequently. In certain dark sky sites, I've even been able to navigate quite well...in star light only...however, I don't think I'd go for a bike ride in those light conditions. Walking is okay but any faster is asking for trouble.

First off this is just pure ignorance!! Where does you logic end? What if you had two sets of car lights that were 2 feet in diameter each that put out 500 watts each, and the man that hit you said "he didnt' see you", does that mean you need 1000 watt light that's 3 feet in diameter to prevent that on your bike?

Good god man get real! the driver that hit you was just simply not paying attention, and you could had a passenger jet landing lights on and he still would have hit you!

If the fear of not being seeing effects you, brighter lights will not help that much especially on a bike because your limited to the size of the lens on the light...though the larger size of the car headlights still did not prevent that jackashe from running into you.

What you need is a bright front flasher to grab motorists attention first, then a light that is bright enough to see by.

I'm in my mid 50's with supposely dimming night vision capability that comes with age; but I see fine with a el-cheapo 13 watt Cygolite dual beam Metro, in fact I see so good I rarely run both beams on! But I incorperated a Vistalite amber xenon flasher to attracted attention to me because I realized the shortcomings of the smaller lens. This fall I added a LED BLT helmet light; but for years all I used was the Cygolite and the Vistalite and never had any problems. I added the helmet light for extra security, and so I could point the light in any direction I wanted like directly onto a car.

When the Metro breaks I may upgrade to brighter light, but I see no reason to go insane with it! I can get more light then I need for the road for around $100 or go with dual Fenix P3's if I can't find anything equal in a dedicated bike light at that time.

Ok

:bored:

??

Good luck man

How much light is enough is completely subjective. Riding at night in the city under streetlights i only need a 1W be seen led headlight. Riding unlit country roads with posible black ice... i want every lumen i can get.

I agree that it's subjective but I come at it from a different angle. An unlit country road? I could ride it with a fairly weak light without issue. In the city? Every possible lumen I can hang on me 'cause I'm competing with a huge quantity and variety of other light sources. I don't want to get lost in that ocean

Question: How much light is enough? short answer: Whatever you feel comfortable riding with in each situation. Me, I likes the the bright ones.

Yup. Plus it's just cool to have the baddest lights around I live for the "Dear God! What is that thing!" comments

Well put. The less ambient light, the less light I need to see by, and the more ambient light, the brighter my headlights need to be.

Bored? then go ride your bike instead of sitting on the computer crying about how bored you are!

Having been out in the rain riding a few times already I have to say I agree with Znomit on the brighter is better. The routes COULD change. If you're familiar with the bumps and such of one road but say you had to change the route because of an accident or something while riding in the rain at night those potholes filled with water look like normal filled asphalt in my experience till you roll into one with a not powerful enough light to penetrate into the water to see that it's a pothole. Weaker lights will reflect off the top and give the appearence of the road is safe when the potholes may have been filled with water.

Brighter is better IMHO as long as you have a few dim modes. Run the light at the lowest dim mode if you don't need that much light but it's always good to know if you're caught in a fog/snow/rain you can bump up the light to the brightest to make damn sure people notice the ball of light out there.

Also going downhills without a strong light is just a bad idea. Especially in a dark or semi-dark area.

What? So some how a brighter light is going to penetrate dark dirty water so you can tell it's a pothole?

Gee if I remember correctly from my days of driving school back in high school that in fog, snow and rain it's better to run with your BRIGHTS OFF. And yes I've ridden in the rain with my "crappy" 13 watt Cygolite at night and have not been in want of a brighter light; in fact I use to do that with just a self contained 4AA battery operated Zefal! In fact in fog, snow and rain you would be better off with the lights mounted on the forks down low near the hub then on the bars.

Ball of light? I remember on this post that one poster was hit while driving HIS CAR with his lights on because the other driver failed to see him; and yet somehow you think this "ball of light" will prevent that?

I use to ride down dark mountains when I lived in So Calif with just my "crappy" 13 watt Cygolite (and also with that Zefal I mentioned above!) and was never worried about the lack of light...but I admit I see better at night then most people.

Don't get me wrong here, if your vision is poor at night, or your riding off road, or going down mountain grades (I'll give you that one) then you may need a brighter light. But again as I stated to the poster about the car that didn't see him with his headlights on, how far do you go with that? If a driver is not paying attention you could be riding your bike with airplane landing lights on and some dopes still won't see you...or maybe their like insects or deer and just are attracted to the light! You need to supplement your bike lights with flashers because obviously you can't ride with lights as big as cars, so your stuck with small diameter lens lights and thus less noticeable.

Well there I go again causing a lot of trouble for you all, I'm sorry, I won't comment anymore about this.

I have ridden in some of the foggiest of conditions. I can tell you that in order to see in that situation you need the light on the bars because on the helmet you can see nothing and actually dimming your lights works better for me and of course aim them lower. Fog makes the brightest lights not so good, which makes lights that you can dim nice.

How much light is enough? ...so long as the ashphalt isn't melting before me I'd say there's room for improvement.

To paraphrase cyccommute's exellent (as usual) post lumens=life

Your comments were boring and the method you employed for communicating your opinions were immature.

dude, you're pushing 1,100 to 1,200 lumens outta that thing
https://nordicgroup.us/s78/wattslumens.html