Sunday, October 28, 2012

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)

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.