Rationale behind the madness
Actually this whole experiment had more to do with overall system flexibility and non-propitiatory power sources than anything else.
Many of the other commercially available LED bicycle lighting systems operate off voltages below 12V. Anything from 5V to 7.5V depending on who makes it. That also locks you into their battery system and puts you at the mercy of product availability.
And then there's charge time. The concept of 1.5 hrs runtime and 5 hrs charge time would just leave a bad taste in my mouth. I'd much prefer the 6 hr runtime/3 hr charge time I'm currently getting.
And although the idea of one light that does everything might appeal to some people - it doesn't too me. Multiple lights give better depth perception and have the option of being split up and used across more than one bike simultaneously.
Of course most people look immediately at weight and lumen output and look at run time last. Personally I'd rather have more run time than 1.5hrs or 2.5hrs and guess what? As soon as you start adding batteries to increase run time on something like a Lupine Betty or a Seca 1400, the weight jumps and the price starts to get even more ridiculous. For a single light anyway.
So the lights I'm using will actually take anything from 9V to 60V as an input which means I can source an amazing range of high quality SLA, NiMh AA power packs, high energy Li Ion Polymer or LiFeO4 cells at a fraction of the cost (typically 25%) of the cost of lower capacity batteries for some of those other popular systems. And some of those I use for other purposes anyway. LiPoly batteries can range from $26 to $160 for the same capacity - the big difference is the discharge rate they'll handle. No point in paying a premium for a battery thas rated at 200A continuous discharge. I'll never need it and the battery won't last any longer.
And since I personally have several bikes, this has worked out quite well. They'll plug directly into the output of the electric bike so no additional batteries required. And because the lights need a minimum of 9V to operate, it's also possible to use unprotected 3-cell high capacity Li Ion Polymer battery packs without over discharging the batteries.
On a run-time per lumen and overall system cost I'm way ahead and total weight is dependent on how many lights I want to run at one time and the size of the battery pack(s) required to do that. These lights are actually mudular in design and can be clipped together to form a rigid light bar if that much light output is required. To arrive at an equivalent point for runtime at equivalent light outputs, I'd have to add several battery packs to a Seca or Lupine system. Those systems would be slightly lighter (slightly), but based on overall flexibility - I wouldn't swap for one.
Helmet mount for Vision X LED lights
Yeah, I know, this is a lot like Playboy magazines - people say they read the articles but without the pictures no-one would buy the magazines. So here's a few photos of the build just to demonstrate what a no-brainer this was.
This Vision X units use (not included) a Trail Tech helmet mount and a proprietary adapter plate. I have several issues with the Trail Tech helmet mounting system anyway:
(1) It can't be aimed
(2) Its intended for full-face helmets as their HID lighting systems are targeted at off-road motorcyclists and downhill bicyclists.
(3) It’s a quick release system that uses a plastic tab that'll break off in cold weather.
(4) The 3M adhesive will also likely let go in cold weather too.
So I junked it.
Then after taking a few measurements, a Zefal MegaBelt Halogen headlamp that had seen a lot of use over the past 20 years was cannibalized. Even if still perfectly functional, it was probably obsolete years ago.
Simply drilling out the metal rivets and adding a couple metal spacers was just about all that was necessary to let the Vision X unit drop in place.
A small cut-out was also made under the light for additional clearance. The thru-bolt is standard issue on the rear of Rollerblade inline skates and needs no machining. A piece of foam to protect the helmet and keep everything in place and you're good to go.
The straps I'm using are Velcro reclaimed from some Zefal anti-flat canisters but any Velcro straps will do the job. This whole conversion thing is literally a 15 minute operation.
The result is solid, can be aimed, is about 10x brighter than the original Zefal halogen headlight, has about 3.25 hrs runtime on 2400mAh AA cells, and is slightly smaller in overall size.
The runtime of the original Zefal MegaBelt halogen was only 2h 20min. Runtime using a Lipo battery depends on the battery capacity of course and can easily be 8 hours with a 6.6Ah 450g Lipo battery. Reasonably sized, plastic housed Lipo batteries are available in capacities up to 12.6Ah but the case actually weighs more than the battery so have to think about it. Cage Rockets weigh less and will already hold multiple 6.5Ah batteries.
I could side-mount two of these lights on the same helmet but that’s overkill for the city and before considering that I'll be testing multiple fork and bar mounted combinations with cut-off lenses and spots to see what gives the most effective light distribution for off-road and on-road use anyway.
The mounts used to fork-mount or bar-mount the lights for testing are Manfrotto 386B Nano Clamps. Weight is 3.8 oz (110g), payload is up to 8.8 lbs (4kg) so multiple lights can be mounted using only one clamp.
Threaded mounts are 1/4-20in and 3/8in female sockets. That's combined with a 3/8in to 1/4-20in converter, a plastic plug, stainless bolt and rubber washer to give a solid mount and keep as much water out as possible. This'll do for testing but I'll probably come up with something more suitable once other details are worked out. Fork clamps for motorcycle steering dampers are a good bet.
The weathers been funny and it’s hard to say how safe the lake is at this point but might have some shots of the power packs and fork and bar mounts up later in the week, even if I can't get some beam shots done on the lake.
So the 'experiment' was a success!
OK So I finally managed to get some shots on the lake in spite of -17C temperatures. Some control or reference photos were also shot just to give some relative comparisons.
I have a couple Blackburn Voyager 2.0 Front Light's mounted, which some people have stated are junk, but I personally find just fine in the city and for day-time running. And just to show how far things have progressed, I also hooked up one of those Petzl MegaBelt 10W halogen headlights from 20 years back too.
In case anyone is interested, those photos were all handheld at ISO 100, f4 and 1sec which were the settings the guys at the MTBR forums decided were appropriate for high power beam shots. Normally they use a 4 sec exposure for commuter lights but I used a uniform time just to give a realistic relative reference. And the coverage is fairly representative of whats in front of you. Real life does have less contrast extremes.
The distance to the wall is 35 feet. The sets of lights were mounted on the same bicycle, except for the headlamp of course.
This is the Petzl which puts out about 35 lumens, is zoomable, and is pretty dismal at either setting.
Attachment 237111Attachment 237110
This is the Blackburn Voyager 2.0 Front Light (two of them). A very narrow beam that lights up stop signs two blocks away but doesn't give great lighting immediately in front of the bike. The Blackburn specs claim 30 lumens and I'm thinking thats a typo cause this is way more than that. A Knog Skink Strobe claims 100 lumens and the Blackburn blows that away so I'm thinking probably 300 lumens.
The pairs of high powered LED lights weren't aimed directly at the wall - they were aimed slightly downwards so that the area in front of the bicycle would be illuminated and the light would not be in the eyes of oncoming traffic.
The high powered LEDs are all made by the same company, use exactly the same P7 Seoul LED, are rated for the same 0.75A power draw, the same 900 lumen output, and were connected to the same power supply and aimed squarely. The difference is entirely the design of the lens assembly.
This one uses a standard 35 degree cone shaped beam identical to what's found in most flashlights and bicycle lights.
The light beam is narrow, and driving on rough roads would still be difficult because it would be hard to access the best route to pick. It has good 'reach, but poor 'spread'. I really don't need to see stop signs four blocks away, but would like to see whats coming up. Also, if aimed upwards to disperse a little more light, the beam will hit oncoming traffic - same as a high beam.
And this other one uses a compound 15/45 degree spread to distribute the light horizontally where its most useful while restricting it vertically to keep it out of the eyes of oncoming traffic.
Not only is a broader area illuminated more completely with the 15/45, it would be very feasible to drive safely with LESS light. Therefore a single light could be used instead of a pair to give better run-times and still provide excellent lighting. And this one is actually easy on the eyes while still being very visible!
Manufacturers can manipulate apparent headlight brightness by using smaller cones. It lets them project the same output into a smaller area producing a brighter light or longer run-times or both. Both 10 and 15 degree cones are even more common (and more useless) than 25 or 30 degree cones. Many beam shots are taken in a manner that demonstrates how far the beam will reach - not how well/poorly the beam illuminates the first 30 to 40 feet in front of the cyclist - which is really the most practical thing for a cyclist.
Personally I HATE tunnel-vision and conical light distribution might be better than nothing, but its not the best aid to safe driving. I need, not only to see where I'm going, but where I might have to go to avoid an obstacle, and also want to see a skunk or raccoon BEFORE it crosses my path!
'Pencil' beams make sense for automotive driving lights where they supplement the reach of high beams at high speeds. Effective near-reach lighting is more appropriate for cyclists based at their driving speeds and the need to avoid what some cars can simply drive over.
So IMO most bicycle lights don't do the job half as well as they could if the engineering emphasis was put on useful light distribution. Which is pretty much why I decided to scrape together something more practical for my own use.
OK So here are some shots out on the lake where there are no range restrictions and no supplemental light sources.
The Petzl just disappears even in a one second exposure. You can just barely see it if you look really, really, really closely.
The pair of Blackburns makes out better but I wouldn't want to drive off-road with it.
A pair of spots is a lot better, but still doesn't quite do it for me.
A combination of reach and spread provided by 3,000 lumens of light directed by paired lenses gives a coverage I can drive at any speed with.
One thing to keep in mind is that these are winter conditions when reflectivity is at a maximum. Spring, summer and fall conditions need a lot more light, on-road and off-road. Asphalt and wet ground both really suck up lumens.
This isn't a $9.99 solution and may not be to everyone's liking, but compared to some of the $900 solutions out there - it looks great to me!