Assembling a Bike Light--Need Advice

--Oops, maybe I should have posted this in Homemade and Modified? Sorry.


I need to put together a light for my bike.

I want to build it myself--because that's more fun than buying one.

I need to assemble it as inexpensively as possible (I don't have tons of cash for this), but I want to use quality components and end up with something I feel good about.

I'll be using the light to commute on country roads--about a 35-40 minute ride twice a day, and I need to be able to see with this light--not only "be seen." That said, I don't think it needs to be super bright--just good enough for bicycle speeds.

Currently I'm planning to run 2 Lux 3 stars behind 20mm optics. I'm thinking about using one oval beam optic for side fill and one tight spot optic for forward illumination--but I really like the ability to swap around 20mm optics or reflectors to achieve the best light for my use.

I plan to use a NiMH battery back in a water bottle--at least initially. I want to use a driver that will give me some flexibility on input voltage so I can switch battery packs or move to a dynamo later.

This is my first LED build, and I need some advice from you guys, if you'd be so kind:

1. What should I use for a housing? Is there a cheap light I can buy and canibalize? Or should I build something out of aluminum tubing or something?

2. What should I use for a driver? I've looked at the "pucks" from LEDSupply, but I am not sure what I need. I'd love something pre-made and easy to hook up--ie. if I can just wire a box to my stars that will give m elots of flexibility with mounting and housing (over a driver that's jsut a PCB)--right?

Any other advice you guys can give me would be great! Am I way off with what I'm planning? Will this make a useble light?

You want advice? Forget the fun of building it: Go for the fun of using it by using a commercial light of your choice from these user reviews.

And forget LEDs. There's a reason they're not favored by makers of premium bicycle lights: They're not as effective at lighting up what you need to see, especially when rain is in the air or on the ground.

You are going more high tech than my first try, but I used a 2-C Cateye as a "mule" (nice QR bracket). It has a 4-D Mag bulb in it powered by a 4-cell NiCad pack in the H2O bottle. Strapped on top in a foam block is the head of a cheap ACO 8-LED light with 8 50K JELED's in it, with a step down resistor and seperate switch. This is not bad under most circumstances alone, but at higher speeds or in ambient light it is nicer with the incan switched on. My favorite beam has to be when I tried my Sam's Element strapped to the bar. I am hoping for an easy upgrade to all LED when Mag comes out with their PR base upgrades for their lights, the Nite-ize bulb was useless. So far I am only in about $14, as I had surplus batteries as well as a few of the smaller bits. Good luck, and based on your results, maybe I will be inspired to do a phase 2.


Paul, I don't ride in the wet if possible, especially at night. That said, I have ridden both types and don't see why LED is not a good way to go, especially for run time. The cost of the really decent comercial systems has kept me away, and I returned the lower-end Night Hawk I tried because it was no better than the Cateye light stock, but wasted about 4x the power.

While I admire the spirit of DIY, :rock: I can see there's a best of both worlds approach available here. Using the reviews from MTBR (which I have been reading for 4+ years) a person could determine which commercially-available elements to emulate and which to avoid.

EDIT: Recommend their sister site : http://www.roadbikereview.com/


My current bike light setup includes a HeadTrip from NiteRider. 15W halogen with the flat NiMh pack, rated at 4.0 Ah. I like the water bottle battery idea, theamazingrando, but I place my flat pack in my CamelBak and mount the light on my helmet. I also have a no-name LED that I occasionally mount on the bars that gives side lighting. More often than not, I rely solely upon the HeadTrip.

I prefer a spot beam on the helmet and a wide beam on the handlebars. There are times when you want to aim your light as far as your eyes can see. Having this light on the bars limits it's usefulness, in my experience.

Putting both types of beams into one package on the bars could be optimal for rando's use with LEDs set up for wide and for spot.

Lucero

I'm gonna have to disagree with Paul. County roads can have different requirements than an off-road trail.

I ride with a mere 1w luxeon on my bike. I ride on pavement and for my needs it serves me well. I also use a generator, so that limits me. From a wattage standpoint. Also, I'm in a town envirnoment, so it is more of a be seen light. I also wear a reflective vest, which I would recommend to anyone who is going to be riding afterdark on roads. You off road types don't need them. For me, always having a light no matter what was more important than having a lot of brightness. The generator ensures that I always have a light (if it failed, I would walk). So far, it has been 100 percent reliable (3 years or so).

Any reviews on MTBR are going to be biased towards off roading. I certainly wouldn't go there looking for advise on road bikes.

No offense intended Paul, I just disagree. County roads do not necessarily mean unpaved roads.

I used a 27mm fraeon optic on mine. Mine is generator powered, so I can't recommend specifics towards your case. I do feel that your selection of two 3w luxeons is excellent for your needs.

Oh, the reason I made mine was because there weren't any on the market at the time (at least none that I could find). No LED generator powered lights that is. I chose LED due to reliability. I used to use a 15w night rider, but it was overkill for my needs.

Do a search on "bike light". There are plans available to build one using a rubber plumbing fitting and a 12v 20 watt halogen lamp. It works great and lights up the night. You should be able to build one with a rechargable battery and charger for under $75. I've used mine for over 5 years.

I just built a 3xLux III bike light using a maglite 2D as a host. Its certainly not dirt cheap, but it is alot of fun building it yourself. See thread at: https://www.candlepowerforums.com/threads/114903

I guess it also depends on what you want for as cheap as possible. High end bike lighting can be more expensive than many bikes (some even approach $1K!!), but for some applications its really needed (e.g. night trail riding or racing). Even on country roads, you might want extra lumens if you go fast... Low-end bike lights will be the cheapest, but they are useless to see by.

My trilux is bright, but not HID-bright (only about half as bright as a typical HID bike light?). Four 120lm K2s would be on par with many bike HIDs though. Could also be cheaper than LuxIIIs(?) It would certainly be adequate for country road riding.

I also have to disagree with Paul in terms of "forgetting about LEDs". LEDs are rapidly approaching many bike HID lights in terms of brightness. And a huge advantage over HIDs is that LEDs are fully dimable. LEDs still have a ways to go in terms of efficiency, but it seems to me that HIDs are just insanely expensive. A third option could be halogen which are cheap. MR16 fits in MagD I think...

I bought two 1Watt (one CR123) flashlights from Target and am in the process of making my own. I'm a woodworker and it's a piece of cake to make one. I can post some pics tomorrow evening of the finished product.
Haven't figured out how to mount it to the bike yet (probably a million ways)because the bike (garage) and the rest of the light (cellar) haven't met yet. It's for a 1 mile commute, but at 11:30 PM.

Sawtooth said:

I also have to disagree with Paul in terms of "forgetting about LEDs". LEDs are rapidly approaching many bike HID lights in terms of brightness.

Click to expand...

It's not that LEDs aren't bright. It's that they have difficulty penetrating
moist air and fog and revealing detail, like that piece of glass in the road.

They're also more irritating if misaimed at a driver's eye.

Paul_in_Maryland said:

It's not that LEDs aren't bright. It's that they have difficulty penetrating
moist air and fog and revealing detail, like that piece of glass in the road.

They're also more irritating if misaimed at a driver's eye.

Click to expand...

With regards to moist air and fog, what makes HID or incandescent better?

Honest question, I'd like to know.

Regarding irritating drivers, the same is true of any light (especially HID). I don't want to irritate drivers, but I'd rather annoy them and have them see me, than not see me.

edit:
Also, the original poster mentioned possibly later going to a dynamo or generator to power the light. This will limit his options. Most generators I've seen top out at 3w@ 6v (schmidt SON being one of the best I've found). All things being equal, I would think that a 3w LED would be brighter than a 3w incandescent. I personally would like to upgrade to a Schmidt hub and a luxeon III, with an oval optic. My current hub is a 2w.

My circuit includes 3 super capacitors to provide a standlight.

The deal with glare is color - the shorter the wavelength the more likely it will bounce and disperse. This is why sunrises and sunsets are amber and red.

Similarly, a lot of fog lights used to have amber lenses, and certain countries (France, for one) used to require amber headlights. This reduces glare and improves performance in foggy conditions.

This is also why HID is more irritating to oncoming drivers - proportionally more of the light is at shorter wavelengths (contains more blue)

What this means is that certain tint LED's (e.g. X1) are probably better than HID, but incandescent is always going to be more yellow and therefore better in fog.

I use a combination of LED and incandescent for my trail riding. 15W Niterider and a L4, occasionally addding a U2 or a Q3 as backup. If you were really set on an all LED solution I'd look into the warmer tinted LED's

I do like MTBR. I was just pointing out that they are going to be biased towards a certain type of rider. Road bike review is going to cater mostly to the spandex crowd. As usual, I fall somewhere in between. I commute sometimes, but I really just like riding around, especially at night, when it is cooler. I ride several miles a day. I also use it to get around town because for me it is more convienant. I can park it easier, and I'm also saving gas.

I've done some of my own reseach regarding bike lights, and for my needs, most of the ones which are suitable come from Europe. They can be hard to find, and as such won't show up on MTBR or as Lucero pointed out, road bike review doesn't even have lights (the spandex crowd only rides in daylight I guess, lights only add weight).

Lights available here (the U.S.) seem to fall into two categories: very bright for off-road use and not so bright. They mostly all are battery powered, the better ones being rechargable.

I'll throw out a link:

peterwhitecycles.com

I'm not affiliated, nor have I purchased from him. He has a nice selection of dynamos and lights. I'm just throwing it out there so you can see what else is on the market.

Like I said, mine was homemade because I couldn't find what I wanted at the time. The machinist in me is embarassed because I haven't made a proper housing for it. The hacker in me is proud because I was able to come up with a good light the first time. Mine has a 1w luxeon that came in a maglite conversion kit. It is a star mounted to an aluminum disk, to act as a heatsink. I used a cut down kodak film canister as a housing for the luxeon and optic. it is held together with tape. The circuit was built on some proto board and is in a plastic bag. This setup has been working for 3 years plus. It looks very unattractive. At first, it was just a test piece, but I've been lazy and have been following the "if it ain't broke, don't fix it" motto. Plus, an unattractive bike helps to keep theives and vandals away. I don't even have a switch on the circuit, so it is always on.

Also, I top out at about 15-20mph on the flats, so I'm no speed demon. We don't have a lot of hills in my neck of the woods, so I don't outrun my light. If you've got some fast descents on your commute, you will have to factor this in. How you ride can also determine your needs.

Whatever you do, use a light when riding at night. Any light is better than no light, and best of luck in your endevors.

Thank you Kromeke!

Paul_in_Maryland said:

It's not that LEDs aren't bright. It's that they have difficulty penetrating
moist air and fog and revealing detail, like that piece of glass in the road.

They're also more irritating if misaimed at a driver's eye.

Click to expand...

Points well taken. Where I live now (northern NM), fog+moist air is not an issue (wish it were at times :laughing, but I am actually worried about irritating drivers (HID would be a problem too in this respect though -- especially since they tend to be brighter).

Here is what you seek:
http://www.instructables.com/ex/i/9129E65EFFBE102880EC001143E7E506/?ALLSTEPS

spyderknut said:

Here is what you seek:
http://www.instructables.com/ex/i/9129E65EFFBE102880EC001143E7E506/?ALLSTEPS

Click to expand...

you beat me to it! i was just looking for the address of exact same site!

Re. fog: best foglight I ever had on a bike was a Lupine Spe-lu (www.lupine.de) made up out of 26 5mm LEDs and mounted low on the bike. Under normal circumstances it wasn't anything special (lots of light but no throw to speak of),
but drive into a fogbank and the whole world lit up.

Putting a light low on the bike is a good idea anyhow, IMHO. Combined with a head-mounted spotlight everything gets lit from two directions, wich makes for better depth perception.

I have been using LED lighting on my recumbent for years

This year is another year for upgrades for my recumbent. The helmet light is a MillerMods L1P for 60 lumens (at the LED) running 1.7 watts from a single AA NiMH. Very bright and when I look at car drivers, they take notice!

My second light is under construction at this point. It will be a 400+ lumen frame mounted light (mounted low under the boom) Andrew Wynn is working on a four Luxeon K2 Mag drop-in mod that has three output levels. Mine will be mounted inside a HA-III bored 2D Mag running 8AA cells. Hoping for four SX1H K2's (60 lumens at 350mA and 105 lumens at 700mA) They will drive through four McR 20mm reflectors and UCL glass lens. I'll set the driver for 700mA (high 420 lumens) 300mA (medium 200 lumens) and 70mA (low 50 to 60 lumens)

For general riding around, running the BAM at 3.6 watt medium (200 lumens) should be fine for riding on city streets. In heavy traffic, punch it to 8.8 watts (420 lumens) in high will outblast ambient lighting and get me around for about 2.5 hours. Couple the BAM with the MillerMods L1P helmet light and I should handle any situation I run into.

Presently, I am eagerly awaiting Andrew's project, the boards are being fabricated so all I need is for Lumileds to produce SX1H K2's... that might take a few months

Does anyone have any thoughts on running a mixture of white LEDs with (switchable) amber ones for fog/mist? The K2 ambers (or Lux IIIs) seem pretty bright...

Took my home-made 2W LED light back and forth from work today (I get out at 11:30 PM) and my $40.00 rig was awesome. Here's a pic. 2 one watt single cr123 Dorcys (Target) in a wood mount 2degrees apart. More than enough light without spending crazy money.