18650 Bike lights

[srolesen]

hey, what flashlights are you use'ing for bikelights now?

i've been looking all over for some simple flashlight (for bikeing) with the following:
1) uses 1 18650 cell
2) xp-g or p7 led
3) 2 modes: 1 low and 1 high (min 1,5 hour)
4) simple tube design, prefer alu for the low weight
and ideally a battery indicator with low, med, high

and i can't find it. so i'm curious, what are the bike lighting enthusiast's are useing these days ?

 

[100g2]

I recently got a spiderfire from dealextreme sku19767works good for $35. A little too bright for oncoming traffic is the only real issue.

 

[srolesen]

wow that's amazingly cheap, is the quality ok ?
and how are the runtimes on low/ high ?

i was thinking of buying this one, http://www.candlepowerforums.com/vb/showthread.php?p=3049988#post3049988

and run it on medium most of the time, but i'm allso conserned that maybe it blinds motorists because of the flood light.

maybe it's just better to just do 2 light and focused aa flashlights ?

I recently got a spiderfire from dealextreme sku19767works good for $35. A little too bright for oncoming traffic is the only real issue.

 

[100g2]

I tested it and it lasts 12~15 hours on low, but not sure on high, high is maybe 4~ 6 times brighter.
Use a 1X18650 X2000 zooming lights from DX next to it instead of a AA light.
You can just use the X2000 in flood mode aimed down where there are oncoming traffic while the P7 in low mode should make you seen and be ready when you need a higher output.
I have been using these X2000 lights for a year and they are great, just order some proper O rings as the included ones are rubbish.

 

[pushy]

You have to angle these flashlights down too far for them to be useful if you want to stop blinding oncoming traffic. The better option is to blank off the top half of the lens with a strip or two of electrical tape and point the flashlight slightly downward and if you're on a trail then rip the tape off.

 

[srolesen]

You have to angle these flashlights down too far for them to be useful if you want to stop blinding oncoming traffic. The better option is to blank off the top half of the lens with a strip or two of electrical tape and point the flashlight slightly downward and if you're on a trail then rip the tape off.

so wich ones do you use ?
nice advise BTW.

 

[yellow]

the focusing lights form DX have absolutely NO SPILL at all, when the beam is not aimed up, noone will be blinded!

btw: the ideal point to point the upper end of the main beam, is about 20-40 meters in front of the bike, thats pointed down some deg.
Sure - with reflectored/opticed lights - the spill might catch other traffic. But thats cars, their lights are 100 W. Any driver not able to stand the slight part of the spill a normal reflectored led light gives, should immediately give the license back.


just never have the light pointed horizontally, thats totally useless.

 

[100g2]

Any driver not able to stand the slight part of the spill a normal reflectored led light gives, should immediately give the license back.

You obviously aren't a truck driver like me who on rare occasions will see some annoying light from 600m+ that annoys and distracts me and I am like wtf is that only to end up being a light on a bike of an inconsiderate cyclist in the early hours of the day. so should I hand my license back? don't think so.

 

[Buck91]

Helmet mount.

 

[pushy]

so wich ones do you use ?
nice advise BTW.

I have had a few Ultrafire C2s, and P7s but these days I use the magicshine P7 bike lights, 2 under the bars with the top half blanked off both and an Ultrafire RL-2088 strapped to the stem, no blanking only on when I need more light. I also have an X2000 cutdown and wired to an external battery pack on full zoom on my helmet. I ride mainly roads and I ride only at night. The X2000 is handy to announce my presence at intersections about 50 yards ahead. The last ones I had were http://www.dealextreme.com/details.dx/sku.22567

 

[BrianMc]

I have had a few Ultrafire C2s, and P7s but these days I use the magicshine P7 bike lights, 2 under the bars with the top half blanked off both

This would work for flashlights, as well. Do you use a reflective cutoff device to try to force some of the lost light back out below the shade, or black tape? Since our 'eye memory' is poor for comparisons of small differences, beam shots with the same camera settings with a mirror as a cutoff device and whatever you are using might be interesting to compare. Aluminum duct tape would be a lighter, (though not as reflective) alternative to a mirror. Just a thought.

If you do this, please post in design a road light thread. Did you try an angled reflective hood to bounce some of the light on to the road? A piece of cardboard with the aluminum tape or foil would work for a test, and a polished piece of aluminum tube would be more weather proof, if it works well enough to justify the effort.

I am planning similar tests once the XPG's arrive and the lights are lit.

 

[pushy]

This would work for flashlights, as well. Do you use a reflective cutoff device to try to force some of the lost light back out below the shade, or black tape? Since our 'eye memory' is poor for comparisons of small differences, beam shots with the same camera settings with a mirror as a cutoff device and whatever you are using might be interesting to compare. Aluminum duct tape would be a lighter, (though not as reflective) alternative to a mirror. Just a thought.

If you do this, please post in design a road light thread. Did you try an angled reflective hood to bounce some of the light on to the road? A piece of cardboard with the aluminum tape or foil would work for a test, and a polished piece of aluminum tube would be more weather proof, if it works well enough to justify the effort.

I am planning similar tests once the XPG's arrive and the lights are lit.

Been down that track with various flashlights. Angled hoods made from pvc/poly tube, tin from soda cans, with and w/o reflective lining. Masking the lens with reflective backing to bounce the light back into the reflector etc, etc. These days I don't bother because there not much to be gained. You don't "lose" much light by masking the top half of the lens with just black tape. Its light that's only going to be in the face of other road users.
Heres an example of poly pipe shade for Fenix L2D with reflective lining

What you see in the pic above is a TK40 mounted on the stem and 2 MCE drop-in modules with the top half blanked with black tape. The red gizmo is a personal alarm wired to a momentary switch.

Sorry I don't mean to hijack this thread.

 

[BrianMc]

Thanks pushy. I hope srolesen will forgive us and maybe find this helpful for his flashlights.

 

[BrianMc]

Hopefully srolesen will forgive more discussion of modified flashlight beams on bikes as being close enough to the thread topic. Making them work well in traffic is a good idea. If not, we can open a new one, and cut and paste these posts.

pushy: did you try a drooping hood? What I mean is a straight out hood only intercepts light that strays higher than the top edge of an imaginary straight ahead beam. Whereas the tape comes down about 40% from the top of the light's face and intercepts maybe 30% of the light. To work in a similar fashion as the tape, and so intercept as much light, the hood would need a downward tilt so the tip was closer to the center of the beam, but how close depends on the light distribution of the light and the length of the hood it won't be as far down as the tape. Did you try different hood angles?

Some ball park estimates are possible. If a hood was tipped down to block the same anmount of light as the tape, say 40% of the beam, since the distribution is bell shaped, that might be 30% of the power in that beam. Reclaiming 30% of a beam with a 10-15% loss on reflection would be 25% redirected. I assume The Fenix's had an XR-E Q5 bin and a 180 lumen max output. Cut off 40% of beam and lets say 30% or light means 136 lumens on the ground with tape and 44 lost. Reclaiming 85% of the 44 lumens would be 35 lumens and about a 25% increase in light to the ground, albeit, closer to the bike. Even that might not be a noticeable difference. That makes it clear why a straight ahead hood with reflecting surface would not be noticeable: the percentage redirected is much smaller than 25%. It is also why a straight ahead hood isn't overly effective on reducing glare to motorists.

That may change with your MagicShines or P7 flashlights. In the case of a light with 6-700 lumens, with a 30% loss to the tape the masked output is about 400-500 lumens, and the redirected light is about the 170 lumens (or a lost output equal to a Q5 at max). Depending on modes available, the light could be run at a lower current for longer runtime or the light could be discarded with so many lumens available. If you used a translucent angled hood, the wasted light would be a sidemarker, as the hood would light up. If too bright, you could black out the top.

Thoughts?

 

[srolesen]

Thanks pushy. I hope srolesen will forgive us and maybe find this helpful for his flashlights.

it's very helpfull:twothumbs
i tried something along those lines, but found that things were getting a little bit heavy, a little bit big, and sometimes got a little bit too complicated. batteries worn out, and heavy flashlights with less than ideal beam profiles brought me here looking for something new.
ideally a flashlight for bikeing could be less than 80g with battery (18650), tube shaped, and with a tail battery indicator. but i have had trouble finding them with a good beamprofile for bikeing. maybe you would just need 2 lights, each with two settings, low and high. 1 for the helmet and one for the bikemount.
as far as i understand there would be a lot af advantages to the above solution like :

• better aerodynamics
• lower weight compaired to larger setups
• no cables
• easy mount/dismount
• easy battery replacement
• easy pill replacement
• theftproof
• better weight/power ratio than nimh
• easy (generic) construction of electronic components for measuring chargestate
• easy (generic) construction of housing
• smaller loss of nightvision compaired to highpowered P7
• no heat problems like big P7 setups
• superior performance in the cold (from li-on tech)
• better long term storage holdup (from li-on tech)
• cheap high performance batteries from generic 18650 formfactor

and i just havent found any flashlight's like that ?
what flashlight's are you useing, and how heavy are they ?
BTW. thanks for interesting pictures/debate

 

[BrianMc]

Sorry. I agree with most of your points, though I don't think they are in order of importance. I had a 12 volt NiMH battery, so I decided against the flashlight route. I would like one as backup, though.

Here is a thread discussing newer 18650 flashlights, since few CPF cyclists with flashlights are responding to your generic question, maybe you can find a specific one to ask about and prompt more discussion?

http://www.candlepowerforums.com/vb/showthread.php?t=251762

There also seems to be some meat here with regard to modules working on a single 18650:

http://forums.mtbr.com/showthread.php?t=569349&highlight=18650+flashlight

There are many hits in that forum for 18650 flashlights, and you can search it from google with MTBR Forum in the search, or join to search within the forum.

Sorry I can't be more help.

 

[pushy]

pushy: did you try a drooping hood? What I mean is a straight out hood only intercepts light that strays higher than the top edge of an imaginary straight ahead beam. Whereas the tape comes down about 40% from the top of the light's face and intercepts maybe 30% of the light. To work in a similar fashion as the tape, and so intercept as much light, the hood would need a downward tilt so the tip was closer to the center of the beam, but how close depends on the light distribution of the light and the length of the hood it won't be as far down as the tape. Did you try different hood angles?

Some ball park estimates are possible. If a hood was tipped down to block the same anmount of light as the tape, say 40% of the beam, since the distribution is bell shaped, that might be 30% of the power in that beam. Reclaiming 30% of a beam with a 10-15% loss on reflection would be 25% redirected. I assume The Fenix's had an XR-E Q5 bin and a 180 lumen max output. Cut off 40% of beam and lets say 30% or light means 136 lumens on the ground with tape and 44 lost. Reclaiming 85% of the 44 lumens would be 35 lumens and about a 25% increase in light to the ground, albeit, closer to the bike. Even that might not be a noticeable difference. That makes it clear why a straight ahead hood with reflecting surface would not be noticeable: the percentage redirected is much smaller than 25%. It is also why a straight ahead hood isn't overly effective on reducing glare to motorists.

That may change with your MagicShines or P7 flashlights. In the case of a light with 6-700 lumens, with a 30% loss to the tape the masked output is about 400-500 lumens, and the redirected light is about the 170 lumens (or a lost output equal to a Q5 at max). Depending on modes available, the light could be run at a lower current for longer runtime or the light could be discarded with so many lumens available. If you used a translucent angled hood, the wasted light would be a sidemarker, as the hood would light up. If too bright, you could black out the top.

Thoughts?

I havent tried drooping hoods, although mathematically your assumptions are probably correct. My prime objective was to reduce the glare to others. Sometimes more light up close is not the best option as you eyes adjust to that amount of light so everything else seems pretty dark. Ultimately I wanted the hot spot as far down the road as possible without annoying the hell out of the guy coming the other way.
As for side visibility, I have wheel reflectors and an X2000 as a helmet light. See this thread.