Red rear light - how bright should it be? Should it be on in daylight as well?

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lumen aeternum

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I'm seeing taillights up to about 150 lumen advertised. With all sorts of blinky/varying modes as well...
I've not seen one integrated with braking, & not sure how that would work, but I understand they exist.
 

kj2

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Lupine rotlicht, is one light that has a brake indicator. Cool feature :)
I don't use my taillight during daytime. Only before sunset, when it's foggy and at nighttime. And I try to stay below 40-50 lumens with my taillight.
Otherwise I'm really blinding others on the road.
 

angerdan

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Red rear light - how bright should it be?
Should it be on in daylight as well?

I'm seeing taillights up to about 150 lumen advertised.
With all sorts of blinky/varying modes as well...
I've not seen one integrated with braking, & not sure how that would work, but I understand they exist.
Even 40lm of red light is so bright, you'll blind people at a distance of 4m (Knog Blinder MOB Mr Chips V or Cateye Rapid X3).

What is important for daylight visibility is a wide beam angle for the taillight.
And a steady or pulse/low frequent light mode.
https://www.bikeforums.net/21037295-post94.html

Using lights during daylight increases safety, since you'll be recognized earlier and as moving traffic.

Go for the Cateye Rapid X2 Kinetic:
cateye.com/intl/products/safety_lights/TL-LD710K/
 

lumen aeternum

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Why did you choose to quote post 94 instead of post 97 which cogently contradicts those claims? [oh - because one of them is you...] (( Actually there are several posts between these two people.)) .

I'd like to know the brightness of an auto/motorcycle tail light -- and have the same beam spread. That certainly does not blind anyone. Any data on whether drivers notice motorcycles better than bicycles?

Wonder how much power auto/motorcycle tail lights draw & if its feasible to be Lithium powered. Looks like bike light features are all Snake Oil -- dozens of competing "modes" but no definitive guidance on when to use any of them. The bike light beamshot page is very nicely done: https://www.bikelightdatabase.com/b...ight]=bc21r&right[mode]=95&right[light]=bc30r
 
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lumen aeternum

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It occurs to me that beamshots on a dark trail are not at all useful. When cars are constantly travelling towards you, your eyes will be constricted more than on a dark road -- so your headlight needs enough illumination to counteract that.
 

BrianMc

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I agree that high output rear lights should not be narrow laser beams but cover a wide range of angles as much as 270 degrees. This video from 4 years ago shows the taillights I use going away from the camera 1/4 mile. I use/used the 1 watt Turbo Superflash in falsh mode, an early Cytolite Hot Spot in swell and shrink mode, and my always on DIY lights. These latter units are about as bright as tail lights of my cars (I can't tell a difference at any rate). The forum crashed when I tried to insert the movie. I will see if the link will suffice:

[FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]https://www.youtube.com/watch?v=wc5DDb6qHbg&t=196s

I have had cops comment favorably and no longer have people tailgate me 3' off my rear fender.
[/FONT]
 

LogansRun

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I would say it should be used during the day. I started to notice when I was in California two years ago that most cyclists had them on during the day.

As for brightness, I have a Knog Cobber large and I used the customize function to use the lower setting + a slow blinking or side-to-side pulse vs. supper bright / fast pulse. When I drive, I know I'm blinded / distracted too much by super bright, high-frequency bike lights. Also, there is that possibility - low though it may be - that some drivers may have a seizure from the high-frequency pulsed lights.
 

onemorejolt

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I am a firm believer in lights ATGATT, all the gear all the time

that means they are there when you need them especially when light fades
Bikes need all the visibility they can get , blinking reds in wide angle and throbbing/pulsing DRL up front.
it is just a part of defensive observant riding.
I have to dodge joggers with poor visible all the time ( Hey , they can see themselves!)


You should be lit up like a Christmas tree that way they start thinking about you from a ways off
More than 40lumens is annoying , though, and the trouble is thy only annoy the folks that didn't need to see them.
 

turbodog

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Agreed. I cycle a lot in the US. I'm making a guess, but I figure drivers here are not as aware of cyclists as in Europe/Etc.

I am running the lezyne zecto drive max, 250 lumens. I have noticed that drivers notice me MUCH more often and at a MUCH greater distance than before. I run it during the day... don't ride at night much anymore.

5 leds that show battery life. Several modes. VERY bright. Good off-angle viewing.

https://www.amazon.com/gp/product/B072NXX76P/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
 

turbodog

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We shouldn't concern ourselves with the lumen output of the lamp, rather we should be concerned with intensity (measured in candela).

Lumens are a proxy for overall performance. If you really want to get down and dirty, you need intensity, viewing angle, and a random flash pattern.

Intensity is obvious, as is viewing angle. Random flash patterns have been show to be MORE noticeable than fixed ones.

Pedal reflectors, at night, are ridiculously noticeable but that's another story for another day (and thread).
 

Alaric Darconville

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