Lighting 2012: Helmet Mount for Headlight Pt II

Like historians, who didn't know to number "The Great War" until the next one came along, labeling it WW-II, I find myself needing to update my helmet lighting again after just a short time.

I was ordering bar tape to match my new saddle and needed to order a few extra bucks worth of something to get free shipping, so decided to splurge and spend $37 at Amazon for a Fenix E25 2xAA cell flashlight.

I almost sent it back when it arrived, because it looked too big. Too big for the mounting system, and too big for the top of a helmet. In the end though, a frontal area only 26% that of a MagicShine was appealing, so I cut it out of the package and tried it in the mount.

Whoot! It fit. Just barely, but it fit. Tight enough I aligned one of the groves in the hand hold area with one shoulder of the clamp on the bottom, but it fits quite nicely. Even with the extra thickness of a star and cut-washer set of lock washers, the bolt was long enough I could get it started by squeezing the clamp shut lightly while starting it in the threads with a screwdriver.

Two layers of Velcro straps go on either side of the Volt's "V". Note topside position of the 3-position switch, sealed by the grey rectangular patch on top

Note how the back half of the shoulders on the shoe are cut away to improve the fit

The retention tab, covered by 2 layers of Velco straps, in addition to the Velcro stuck to the shoe and helmet, provides excellent front-to-back stability.

Light is mounted slightly behind the center of gravity to allow angling it up enough to point it well up the road when in the aerobars

Minimal frontal area and low-profile mount makes this aerodynamic, silent, and keeps the weight from shifting the helmet around.

The E25 is a little long. An E35, powered by a single 18650 LION cell would be better, but the price is close to that of a Cygolite then, and this mount doesn't allow you to slip the light off when riding in daylight. It does allow you to walk into "Bertha and Bubba's Bait Barn" anywhere in the US and buy AA alkaline cells on double centuries.

The involvement on the inside of the helmet is minimal, and being a soft mount, doesn't compromise the structural integrity of the helmet's protection in any way I can detect.

This shoe got covered with an inch of soft-side Velcro which added a lot of stability when interfacing with the scratchy side Velco stuck to the helmet

The "Velcro" comes in rolls, and isn't Velcro, but a Chinese rip-off with smaller loops and hooks. It is just a bit stretchy, which really helps when doing a soft mount like this. The Fenix LD01 is pictured here for scale.

I had already futzed around with the Velcro on the mounting system before trying this, but note that the new approach is cleaner and more stable. The changes to the system are as follows.

1. I cut the shoulders off of the shoe about half way from back to front to get a better straddle over the helmet's raised "V"
2. I ground the shoe's retention pip off on some concrete (crude, but effective) to make the shoe completely flat
3. I covered the flat part of the shoe with a strip of self-adhesive soft-side Velcro to interface with the scratchy-side Velcro already stuck to the helmet top
4. I ditched the red Velcro strap running side-to-side as the mount is completely stable side-to-side now without it
5. I added a 2nd layer of front-to-back mini-Velcro, running one layer on the right side of the Volt helmet's leading "V",  and one layer on the left side
6. I added a star lock washer against the plastic of the mount, and a cut-washer type lock washer against the bolt head. This keeps the screw from unscrewing itself when you work the tilt mechanism back and forth when transitioning from the blocks to aerobars and back.

In the end, what made the decision to keep the E25 easy was it's extremely tight beam pattern -  1.5ft @ 25ft, and able to paint reflective signs at over 5 blocks. It lit up the dozens of trash cans in the bike lane on California Ave for 2 blocks ahead, and almost blinded me when I accidentally bounced the beam off of a 4x4' yellow speed caution sign.

I also appreciated that it was very easy to point away from oncoming riders on the ARPT by pointing it at the shoulder 20ft ahead, knowing that almost no light was spilling out into the oncoming rider's eyes. I had no difficulty at all seeing where I was going, even looking into lighting in the 2,000 lumen range from multiple bikes riding in a paceline. It's that bright! (rated at 156 meters, and it's all of that)

In talking to endurance riders, those that ride double centuries, Brevets, and 500+ mile rides, as well as devoted night riders and commuters, one thing comes up again and again. The battery life of headlights should be at least 2X your greatest need on the highest setting. The alternative is constantly 2nd guessing yourself about how much light you can afford to use, fearing complete darkness. The more challenging the ride, the less welcome this constant nagging thought becomes.

I'm going to try a single 18650 cell flashlight just for grins, as it will be smaller and should last longer, having 1 X 3.7v X 3,000mAh or 11.1 watt-hours of energy stored, v.s. 2 X 1.25v X 2,700mAh or 6.75 watt-hours of energy, and will be lighter as well.

In the end, everything is going to be powered by 18650 LION cells, because this is what electric cars, like the new Ford C-Max Energi are using. CygoLite uses these in removable packages in many of their lights, but as yet, you can't walk into a gas station in a remote area and buy them like AA cells. 

If you give up on a battery solution for the duration of the ride, then by all means go with batteries that are readily available along the way. The 1st time you are humping a bunch of dead batteries up the side of a mountain 10-12 hours into a double century, this will become abundantly clear.

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Lighting 2012: Helmet Mount for Headlight Pt I

What started out as a map light to light the Garmin 305 Edge, thermometer, and the tops of the bars morphed into a headlight as well with the incredibly bright Fenix LD01 "pen light", which puts out 85 lumens on high.

The one frustration I've had with this light, is getting it to tilt up for lighting the road properly, especially when riding down in the aerobars, and down again when I want to read my Garmin or thermometer.

With an upcoming 25 hr noon-to-noon ride on the 4th, when we "fall back" to end DST for 2010, I wanted this problem solved. I started looking at the mounting options I had laying around, and in an epiphany, I realized that the body of the Fenix is the same size as the seatstays on most bikes, so by swapping the roles of the clamp and the mounting shoe, I could make a perfect flashlight holder, purpose made to tilt.

The first mount I made was for my Bell Volt Helmet, and then, just to test the flexibility of the Velcro approach, I did another mount on an old Bell Ghisalo helmet, where the shoe fits down into the vent hole on top of the helmet, so is VERY streamlined.

Despite the scale these close-ups seems to imply, these lights are not much bigger than the AAA cells that power them - very GOOD AAA cells would be my suggestion. I'm using mostly Sanyo 1000mAh cells, and carry 2 extra batteries in my saddlebag, in addition to the 6 that power the taillights.

The red Velcro I got from an auto parts place, and the black from Amazon. The black version is not Velcro, but some "hook and loop" system, which scaled down in every way, and doesn't interface well with the normal sized Velcro. Both work well, and it's nice to have the flexibility of 2 sizes, but they won't stick to each other properly.

I've also replaced the Blackburn Mars 3.0 with a 4.0. It's easily 3-4X as bright, about half the size, weighs slightly less, has the same mounting system, but is sans the rarely used "marquee" flash mode. It still, stupidly, uses colored lenses when LEDs already produce the proper color all on their own, so the colored lens just blocks light needlessly. Planet Bike has wisely used clear lenses, and a translucent white body so the whole case turns red in constant-on mode.

On the plus side, the Mars lights have a simple flash pattern that can be tracked, not as well as in constant-on mode, but still trackable in a pinch. Their hose clamp mount makes for easy helmet mounting, and they have amber lights on each side to properly indicate to traffic they're looking at you from the side. (reflective tire sidewalls and wheel reflectors do this too)
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Before, with Blackburn Mars 3.0 taillight and Velcro mount

After, with Blackburn Mars 4.0 and Velcro-ed PB seat-stay mounting system with dyslexia.

Velcro running in both directions for a good anchor. Note the lock tab forward where the back Velcro passes over it before being threaded into the inside of the helmet.

View of the inside of the Bell Volt helmet. Always run Velcro UNDER the helmet's sweatbands.

2 layers of Velcro under the shoe. One sticking to the helmet, and one on top of that (red) running under the PB mounting shoe

Close-up of mount. Easier to do the Velcro work with the clamp OFF, especially when running the black Velcro across the top of the red.

Note the receiving slot of the PB mounting shoe clearly visible here. I may cut the vertical part of the shoe off later and put some adhesive Velcro on the then flat shoe to make this an even more stable mount.

Fenix LD01 flashlight is mounted right at the balance point so it will have no tenancy to tilt up or down

The lock tab on the PB mounting shoe is clearly visible on the front side here

Bell Ghisallo helmet with PB receiving shoe mounted down inside the top vent hole

Black Velcro holds the shoe forward, tightly against the tapered front of the vent hole

Note rubber spacer wrapping the flashlight. Its cushion is required to allow the teeth in the tilting mechanism to slip past each other. Also note that the slotted holes in the wide part of the red Velcro were both worked down around the leg on the shoe that holds the clamp to it. With Velcro running in opposite directions, this makes for a great side-to-side mounting system.

These Velcro straps have just the right amount of stretch for this application, although the mount benefits from a rather tight cinching. It's also worth noting that using this same approach, a pretty large flashlight, or headlight, could be mounted if the small clamp were replaced with the large clamp.


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Techie Tuesday: Mounting Helmet Lights

After crashing in Feb, I replaced my Bell Ghisallo with a Bell Volt, and have had to experiment a little to find good mountings for my summer lighting. The Blackburn MARS 3.0 taillight was pretty easy, and very similar, but mounting the Fenix LD01 flashlight in front, to use as a map light, and/or emergency headlight, required some innovating.
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Overall, a pretty light and slippery lighting system. The Fenix starts in Med mode, and is switched by quickly twisting the front of the light to toggle it through its 3 settings. Med-Lo-Hi. Nice that that's a 1-handed operation!

MARS 3.0 taillight is offset 2.5" from the back of the helmet, which makes it visible except from directly ahead. Combined with the headlight, it makes it easy for motorists to figure out where I'm looking at night.

The Blackburn mounting system uses what is essentially a plastic hose clamp. It works very well with the addition of a wooden dowel as a "soft" spacer. No need to over tighten. Easy does it!

Mounting system is minimally intrusive on the human side of the helmet

Bug's-eye view of the Fexix LD01 "headlight"

At .5oz for the Fexix, and whatever the AAA weighs, this little guy (20mm) is 1/10th the weight, and 1/5th the size of most headlights, so it doesn't grab much wind, nor block your helmet's cooling vents

A little hook-side Velco stuck to the helmet, and then a Velcro wire bundle tie looped over the top, makes a nice soft, movable/adjustable mount for lighting the cockpit, and/or, the road.

The back of the flashlight body was wrapped in a 3" strip of soft rubber gripper, held in place with a tiny zip-tie. It was pillfered from another mounting kit. Hollow back aids cooling.

Detail of inside of Velcro mount. Note it is "clamping" on solid Styrofoam, so not compressing two unsupported slots together.

I left a small slot at the top of the flashlight uncovered when wrapping it with loop-side Velcro, to allow for better cooling. The light, if anything, tends to push air into the front slot, and suck it out of the rear slot, improving overall ventilation

Based on a suggestion made on Amazon.com, I inserted a LION 10440 cell into the Fexix LD01. It's very bright anyway, but the 72 lumens jumps to about 225 with 3.7 volts pushing it, instead of 1.25 volts. On the lowest setting it produces about the same light it's supposed to on the 27 lumen setting. On med, about 100 lumens, and I'm scared to leave it on high for more than a minute as it gets hot fast.

I'm going to experiment with this setup a little, but can't recommend it at this point. On low the 10440 cell only lasted 2.5 hours, so not much on endurance. I may try the medium setting with the flashlight in my freezer just to see if it's the LION cell's voltage regulation circuit that is limiting it's burn time, not power drawn. Happy trails!