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K'Tesh
11-16-2008, 11:44 AM
http://farm4.static.flickr.com/3143/3035129731_03d6de2cc6.jpg (http://www.flickr.com/photos/ufobike/3035129731/)

All to often, bike riders will ride after dark wearing, wearing dark clothing, on dark bikes, without the advantage of reflectors or lights. Reflectors only work when car is already aimed at you.

Ride a bicycle?

got lights?


Be Seeing You...
K'Tesh


Feel free to print this image and use it wherever it could do the best work. Do not try to profit from it.

Jeff Wills
11-16-2008, 06:42 PM
got lights?


Got light colored jacket? Here's a web page that illustrate the problem:
http://www.bikexprt.com/witness/fabric/analysis.htm
And a good analysis of a couple solutions:
http://www.mechbgon.com/visibility/index.html

wyeast
11-18-2008, 08:26 PM
imho, the best is to have both reflective and active illumination. Lights are key when you're coming into cross traffic or other situations where reflectors won't help.

On the other hand, retroreflective gear will vastly outshine most tiny bike lights when hit full-on by automobile headlights. There just is no substitute.

And please. Please. Do not forget to take into account how you're positioned on the bike. All too often I'll pass someone w/ good intentions, clipping a blinkie onto their messenger bag, only to have the light flashing towards the sky as they crouch over the handlebars.

Be safe out there!

lefty175
11-19-2008, 10:43 AM
I'll pass someone w/ good intentions, clipping a blinkie onto their messenger bag, only to have the light flashing towards the sky as they crouch over the handlebars.

Amen, that or they're carrying on load on their rack and it's obscuring their seatpost blinky. I have two back lights and one front (trinewt) light on my bike, but I've also taken to placing reflective tape along the front fork, downtube, and the rear fender to have some passive illumination.

K'Tesh
11-19-2008, 10:57 AM
Amen, that or they're carrying on load on their rack and it's obscuring their seatpost blinky. I have two back lights and one front (trinewt) light on my bike, but I've also taken to placing reflective tape along the front fork, downtube, and the rear fender to have some passive illumination.

I took that a little bit further...

http://farm4.static.flickr.com/3073/2697187055_31aafaeb98_o.jpg (http://www.flickr.com/photos/ufobike/sets/72157606341007268/)

For more info on how to do this yourself, consult the Glow-in-the-Dark Bike (http://bikeportland.org/forum/showthread.php?t=1357) thread.

Be Seeing Ya!
K'Tesh

Oldguyonabike
11-19-2008, 01:14 PM
I just picked up a roll of 3-M reflective tape at Ace Hardware for $3.50. There was enought to run a strip down my rear fender, rear forks and front forks. Set it out on the curb against a tree and then pointed my car lights at it from a block away and was amazed at how it lit up.

K'Tesh
11-19-2008, 02:16 PM
I just picked up a roll of 3-M reflective tape at Ace Hardware for $3.50. There was enought to run a strip down my rear fender, rear forks and front forks. Set it out on the curb against a tree and then pointed my car lights at it from a block away and was amazed at how it lit up.

A picture's worth a thousand words... Please, Let us see your handiwork!

Rubberside Down!
K'Tesh

Oldguyonabike
11-19-2008, 03:15 PM
I'm a bit of a Luddite. No cell phone. I do have a digital camera but I haven't a clue how to get resolution in the dark and then download here. Look for me on SE 92nd and wave!

K'Tesh
11-19-2008, 03:24 PM
I'm a bit of a Luddite. No cell phone. I do have a digital camera but I haven't a clue how to get resolution in the dark and then download here. Look for me on SE 92nd and wave!

No harm in trying

I wouldn't worry about blurry images/resolution in the dark, just try to take a pic. Then you can and either attach it, or PM me for my email, and I'll upload and attach it.

Best results for night shots... find something to set the camera on (like a tripod or a fence). Shine a light at the bike. Hold breath, take picture, release breath... (continue breathing). I found that breathing while taking a night shot lately has a wonder effect of creating that cloud that you see when it's cold out (and ruins the shot).

Rubberside Down!
K'Tesh

DogsBody
11-24-2008, 01:48 PM
My friends accuse me of looking like a Cop Car at night.
I actually had a buddy who was walking to a party we all went to this weekend who saw me go by and said, "I thought it was a cop on a Motorbike until I realised the motorbike wasn't making any noise"...:D
Here's an entertaining little vid made by Amy Walker over at MOMENTUM concerning this subject:
http://www.momentumplanet.com/news/lets-get-visible

bubbaPDX
12-01-2008, 02:21 PM
My dark evening bicycle commute on the Springwater Corridor gets me thinking about lighting and safety. In particular, the relative safety benefits of "strobing/flashing only" versus "steady only" forward lighting at night.

In dark surroundings -- where the silhouette of an approaching cyclist is not visible -- I find the strobing/flashing forward lights disorienting. That is to say, I have a hard time gauging the approaching cyclist's position, trajectory, closing speed, etc. based only on a disembodied (and often intense) flash of light. In contrast, an approaching "steady on" headlight is easier to track and maneuver around.

This would also be an issue in rain, fog and snow.

I recalled some research done by my former colleague for the NRC Transportation Research Board
(http://www.lrc.rpi.edu/resources/pdf/iesna01a.pdf).
Apparently, snowplows with strobing rear indicator lights were getting rear-ended by other motorists in low-visibility conditions. My colleague hypothesized that strobing lights were " less effective than steady-burning lights at providing cues about relative speed, distance and closure." This hypothesis was supported by earlier research. The LRC research indicated significantly shorter reaction times (i.e., determining that you're approaching the snowplow) for the "steady on" lighting versus the strobing configurations.

Which of course isn't to say that a flashing bike headlight isn't useful. I use mine in daytime for conspicuity... it increases your chance of being detected in a driver's or pedestrian's peripheral vision. I think that it's also important in nighttime, high-traffic conditions to (hopefully) better distinguish you from the jumble of surrounding vehicle headlights. However, in poor visibility conditions -- most commonly rain -- the pavement goes dark and cyclists begin to appear as disembodied flashes of light.

My approach for nighttime forward lighting is a combination of flashing (for conspicuity) and steady (to 1. help me see the road & obstacles; and 2. help others gauge my position, trajectory, etc.). After a brief go with a NiteRider MiNewt Dual (battery freaked out), I'm rolling with an Exposure Enduro Maxx
(http://www.exposurelights.com/products/enduro_maxx/index.php)
as discussed on
http://reviews.mtbr.com/blog/category/lights-shootout/ .
More than enough light output, with excellent steady-on-plus-strobe flash mode. Thumb switch (on backorder) will let me dim the light to spare fellow Corridor riders from convulsions, seizures, blindness, etc.

I guess we could have the same conversation about taillights.

What's your experience... as a cyclist? Motorist? Pedestrian?

Cheers, >>bubba<<

djasonpenney
12-01-2008, 04:55 PM
Strobing lights are (purportedly) completely verboten in Germany. I hadn't heard the anecdote about snow plows, but it's probably this is the sort of concern that der BundesReichBikers must have had.

lynnef
12-01-2008, 05:35 PM
from Randonneurs USA (rusa.org)
Article 10

For night riding, vehicles must be equipped with front and rear lights attached firmly to the vehicle. Lights must be turned on at all times during hours of darkness or other low-light conditions (rain, fog, etc.). At least one of the rear lights must be in a steady (rather than flashing) mode. All riders' lights must meet the requirements of local laws. A rider is not permitted to cycle at night or in other low-light conditions without working front and rear lights attached to the vehicle; therefore backup lighting systems and/or spare bulbs are strongly recommended in case the primary system fails and cannot be repaired on the roadside. Each rider, whether riding in a group or alone, must fully comply with this requirement. Everyone must use their lights!

During hours of darkness or other low-light conditions, all riders must wear a reflective vest, sash, Sam Browne belt, or some other device that clearly places reflective material on the front and back of the rider. During these times all riders will also wear a reflective ankle band around each ankle. (Due to their unusual seating position, recumbent riders may modify their reflective torso devices to show better from front and rear.) Other reflective devices on clothing, shoes, helmets, and machines are encouraged for increased safety - but they are extra and may not take the place of the minimum items listed above.

Any violation of these night riding rules will result in the immediate disqualification of the rider.

wyeast
12-02-2008, 07:02 AM
I'm a strong proponent of having steady and flashing. Both to provide a steady light for referencing position/speed; also having two distinct light sources provide an additional reference to position. (as you get closer, the two lights appear further apart)

Then there's of course the redundancy factor if one light goes out. :D

djasonpenney
12-02-2008, 08:56 AM
One concern I have is that the profile of bicyclists is so small that it may not make any difference whether or not the lights are flashing. It is possible that motorists will have depth perception issues with respect to a cyclist regardless of whether or not the cyclist's light is flashing or steady.

My point is that we can't assume that the snow plow finding is directly applicable.

FWIW, in low light conditions (esp the entire months of December and January here :)) I will run a blinking front light, but at night I run full intensity (approximately 700 lumens) without any flashing whatsoever.

On the rear, I have three blinkies, including a Planet Bike Superflash, and another that I attach to my left ankle in order to additionally provide the characteristic sinusoidal up-and-down motion of pedalling. I've been running all of them in blinking mode, but after the discussion here I think I'll start running one of the three in steady mode. I still believe that the flashing mode is better at getting the motorist's attention, but it certainly wouldn't hurt to give them a steady point source as well.

One foggy morning last winter on SR-47 north of Forest Grove driving to a randonneur start, we saw a bicyclist (a farmhand, I suspect), riding in full dark. We could see his rear light as we approached, but dang if we could tell how away it was. Based on that experience, I doubt that anything short of two steady point sources situated multiple feet apart would help a fast approaching motorist accurately judge distance.

djasonpenney
12-02-2008, 11:05 AM
http://www.mechbgon.com/visibility/index.html

yet another take on the issue...

bubbaPDX
12-03-2008, 12:39 PM
Thanks djason for the mechbgon link... points to a "systems" approach -- not to mention a sobering reminder that motorists' behaviors are beyond our control, regardless of how "visible" we think we may be.

Quick comment on lumen claims by manufacturers. Perhaps with the exception of NiteRider (used as a benchmark in the mtbr.com LED shootout), bike light manufacturers do not typically perform photometric testing on their products. It's expensive, for one thing. Consequently, the claimed lumen outputs are usually from the LED manufacturers, for individual chips on a test stand, operated for milliseconds at a standard current and voltage at an ambient temp of 25 deg C.

LEDs lose light output (and life) at elevated temperatures, and these thermal losses are further compounded by secondary optics (lenses, reflectors, etc.). So, depending on the electrical, thermal and optical design of a bike headlight... who's to say where your actual lumen output ends up? My Exposure Enduro Maxx is rated at "720 lumens"... don't think so. But -- qualitatively -- the light works well, with ample intensity and a useful beam pattern.

So much for my quick comment. Buyer beware the lumen claims and numerical one-upmanship! Photos of beam patterns (http://www.mtbr.com/dualbeamcomparisoncrx.aspx), user reviews and YOUR OWN IMPRESSIONS may prove more useful. Enjoy the "Season of Light!"

bubbaPDX
12-03-2008, 12:46 PM
Any idea of runtime for the Planet Bike Superflash in "steady" mode?

Also, does it "fade" as the battery draws down, or maintain brightness and cut off at some point?

Thanks kindly!

lazlo
12-05-2008, 08:27 AM
I use one of my PB Blinky Superflashes on solid. Been running 1.5 hrs per day 3 days per week for 3 months with no noticeable decline in brightness. Don't know if it will just dim or quit when batteries get low. I've found in flash mode batteries tend to last me as long as 6 months.

K'Tesh
12-05-2008, 08:37 AM
I use one of my PB Blinky Superflashes on solid. Been running 1.5 hrs per day 3 days per week for 3 months with no noticeable decline in brightness. Don't know if it will just dim or quit when batteries get low. I've found in flash mode batteries tend to last me as long as 6 months.

Are you sure of that? I notice that my lights using older batteries start out bright, but fade... I'd advise checking the brightness after your ride, not when it's just out of the gate.

Still, it's good to hear you're getting the miles in even after dark.

bubbaPDX
12-05-2008, 08:56 AM
Lazlo: Thanks for the data! I've been thru one set of batts on one Superflash... all in flash mode, and I recall that it just stopped working (I could be wrong).
K'Tesh: I noticed that my Cateye blinky took the "fade" approach.
Will continue investigating.
Thanks, all!

bubbaPDX
12-05-2008, 11:03 AM
According to manufacturer, PB Superflash runs bright, then cuts off (see below).

-----Original Message-----
From: info [mailto:info@planetbike.com]
Sent: Friday, December 05, 2008 12:04 PM
Subject: Re: Superflash runtime question

Your #1 is the answer. No gradual fading will occur, it just won't turn on when the battery power is below a threshold.

Mark

bubbaPDX wrote:
>
> Good morning,
>
> Curious about "battery management" on the Superflash blinky. Does it:
>
> 1) run at full output (steady or flash) and then cut off when battery
> power drops below a threshold; or
>
> 2) "fade" as the battery discharges?

bubbaPDX
12-16-2008, 11:57 AM
This from the OregonLive.com
[http://blog.oregonlive.com/commuting/2008/12/can_you_see_the_light_maybe_no.html]

Can you see the light? When LED signals and snow mix, maybe not

Posted by Joseph Rose, The Oregonian December 14, 2008 16:57PM

Categories: Breaking News, Hard Drive column

Those new-fangled, low energy LED lights directing traffic in Portland area intersections are great at saving cities money. But when it comes to melting away snow during a blizzard, they're not so bright.

Snow and ice accumulating on the signals today have caused headaches and a few fender benders. Unlike the old incandescent light technology, the red, yellow and green LED's "don't generate enough heat to melt away the ice and snow," said Dave Thompson, an Oregon Department of Transportation spokesman. "We're asking people to be aware of this problem."

It doesn't help that lights are shielded by crescent-shaped hoods, where snow piles up and keeps any illumination from escaping, Thompson said. With the lights completely covered, drivers can't see who has the right-of-way and many are trying to roll through intersections at once, he said.

"When the lights are covered with snow," Thompson said, "those intersections should be treated like four-way stops."

K'Tesh
12-16-2008, 01:29 PM
"When the lights are covered with snow," Thompson said, "those intersections should be treated like four-way stops."

Amazing how many people forget that...

Also I'm amazed at how many drivers are driving after dark w/o their headlights on. Makes me wish there was some kind of universal hand sign (using all fingers) that would advise motorists to turn on their lights...

Rubberside Down!
K'Tesh

appologizes to Peter Wolf (http://www.mtv.com/lyrics/wolf_peter_1_/lights_out/5041647/lyrics.jhtml)...