Okay! The clamps I need finally came in, and I got a chance this weekend to fab up some mounts. Originally I had planned to mount the whole thing to the handlebars, but then realized it would be more efficient to simply attach the lights to the front fork just above the brakes. The lights are more out of the way in this configuration.

I used two 1.25" galvanized steel clamps on each flashlight, slightly modified to tightly hold the 1.1" diameter flashlight body. The clamps are paired in a sort of figure-eight pattern with those on the other flashlight, so that only two screws are needed to attach all four clamps to the mounting bracket. The bracket is made of a 4" piece of 1/8" aluminum I scored for free from my company's machine shop. The bracket has a single 90 degree bend and a drilled hole to attach it to the mounting hole in the front fork.

I also bought some glossy black paint to de-uglify the steel and aluminum, I'll probably paint the assembly tonight after I've tested the light to see if it fits properly. Heh, now that I think of it, there are an innumerable number of ways I could have mounted these lights to my bike, all you need is the right diameter clamps.

Anyway, the only thing I have to worry about now is how secure the fork-mounted plan will be. The flashlights are all-metal, so are heavier than most commecial plastic-built models. I'll have to make sure that the light assembly not only doesn't droop (unlikely) but also doesn't slip to the side and hit my wheel! Perhaps a single black zip-tie will help in this regard. ;)

Another interesting thing, I seem to have manage to align the beams so that they are directly on top of each other between 5 and 10 feet. After this point, they diverge again. Naturally a little force will bend the mount so that the lights are aligned however I want, but it's interesting that they came so close by accident.

So, once this is done I will begin on the rear lights. I have two options, I can make ground FX lights like multibiker's (only in red), or I can make an LED light bar out of about 4 dozen 3mm LEDs. I already have the red luxeons (in all their retina-burning glory), and the rigid plastic tube to build the LED light bar.

Does anyone have a cool idea for the best place to locate a switch? Under the seat may be cool, I dunno. A sealed magnetic switch would be awesome, but I don't know how I'd configure a magnet to work with it...

Light geeks: LED MR16 Bulb?
 

Have any of light geeks here used a LED MR16 bulb? Something like these: http://www.superbrightleds.com/specs/mr16-wlx-spec.htm

They claim the 3w LED has roughly the brightness of a 20w halogen. If that's true it would be quite revolutionary. It's a little steep at about $25.

I've never used one of those but a beam angle of 25 deg. is more of a floodlight than a spot. That would limit how far ahead of you it will light, although it would be very good for being seen. I agree if it really worked out to be as bright as a 20w what a great thing for battery life.

I used the 100 degree, 3w LED, MR16. At that wider spread it was more like 8 to 10W halogen. I did run into a problem with the LED/reflector portion separating from the base. I'm re-thinking how I set it up & planning on getting a new one.

My LED headlights are DONE. Now all I have to do is mount them to my bike. Pics posted when I have them!

I run two headlights. Both are small Union housings with screw base halogens. I put one 6V 6W halogen in the right side and a 6V Super Bright LED cluster in the other. This was supposed to help on battery run time.

The LED did ok on my way to work. On my way home I had a melt down. I took the LED out and it was a ball of burnt plastic. It got too hot in the housing. :(

I went back to 6V 3W and 6V 6W. I'll keep watching this post to see what you guys come up with. BTW, I did find out one interesting thing. LEDs like to be powered one way. I had to re-wire one side of my lights. LEDs like to be powered from the bottom and ground through the side.

LEDs are diodes, and can ONLY be powered in one way. The have a polarity, a positive and negative (or more correctly, an anode and cathode) end. If you hook them up backwards for anything more than a fraction of a second they will become damaged and quickly burn out. I've not heard of an LED actually melting due to reverse current however.

I suspect that the LED cluster you were using was either rated for a lower voltage, or had no current limiting at all. One thing that CAN cause an LED to melt (though again is more likely to simply burn it out) is excessive current.

Another thing to consider is that although many people think LEDs are devices that always run cool to the touch, this is not true. Relatively dim LEDs used to show that your TV is on certainly run cool, but LEDs that illuminate the road are not. They can dump out several watts of heat just like a halogen, but thisheat must be removed with adequate heat sinking or the LED will become damaged.

The LEDs in my headlights are thermally connected to the aluminum bodies housing the lights, which in turn are clamped to the frame of my bike (though the amount of heat that actually reaches the frame is quite low due to inefficient heatsink design on my part).

jharte, are those "small Union housings" made of plasitc or metal? Just wondering...

Plastic lenses but metal housings. I considered puting a vent in them but I would lose my weather-proofness.

BTW, I did a quick search on 6V vs. 12V and didn't come up with much. My 6V battery is getting old and I will soon have a choice. I see many of you use 12V and was wondering why.

When you have a 12 volt system it opens up the world of lights/electrical stuff made for cars, trucks, boats and low voltage landscape lights. If your light goes out or you need a new fuse, you can find something to work at the nearest auto store or home center.

A vent wouldn't have helped anyway. The LED cluster would need actual heatsinking, meaning a metal portion on it should be thermally connected to a larger heatsink (ie. the body of the lamp). However, the lamp would also need to be of a certain size, depending on the heat output of the LEDs, in order to properly dissipate all the heat.


And about 12V. As said before, there are a lot of lighting solutions availavle that run from 12V. There are also many rechargeable 12V batteries available for a good price. Put those two together and you have a great solution for most applications.

You may want to look into getting an external portable DVD player battery to use as your power source. These can be found in 7.2, 9 and 12 volt variants, up to several thousand mAh. The one I use is 9V, 5400mAh. The best part about these batteries is that they use lithium-ion technology, which packs far more energy density in a lighter package than regular lead-acid, ni-cad or nimh. These batteries also usually have a built-in charge controller and adapter, so all you have you have to do when the battery is drained is plug it in to the wall. The unit I have even features an LED readout of remaining battery power.

This looks very interesting -- a MR-16 fluorescent bulb ! They claim 2.5 watts at 12v, with the light of a 20 watt incandescent.

It's sold for use on sailboats. Price is $24.95

http://www.sailboatstuff.com/lt_G4_MR11_MR16.html Scroll down to the bottom of the page.

The same page also has Xenon MR-16 bulbs in 10watt and 20watt, which look interesting as well.

I just ordered a set of the Optronics driving fog lights that seem to be popular, and I thought I'd throw down a few comments for posterity.

I got it from JC Whitney. Item # is ZX490431P. Here's the URL: http://www.jcwhitney.com/autoparts/I...D:100000201440

The cost is 14.99 which gets you two lights, an illuminated switch, and a pretty good wiring harness. All in all it's an impressive deal. There are a couple of things wrong with the web site listing. It's listed as a 55-watt h3 bulb with a clear lens. It actually comes with a 50-watt MR-16 bulb that is tinted yellow. It's also listed as round when it is quite oval in shape. These errors don't really matter as the 50 watt bulb draws too much current for most cyclist use.

The reason I like this one is that the MR-16 seems to be rapidly developing a lot of bulb alternatives. You can now get version in halogen, xenon, LED, and fluorescent, ranging from 2.5 to 50 watts, in a variety of beam shapes. I replaced the bulb with a 20 w halogen, 30 degree beam I had lying around. It makes a pretty good bike light. One thing I like is that it is well shielded to the rear.

It's made of plastic and weighs a few ounces.

I did a side-by-side comparison with my current commuter light, which is a 25 watt 4" sealed beam PAR36 LV505 halogen bulb. The sealed beam gives more light and is more visible, which makes sense since it has more power and four times the reflector area. On the other hand it is bulky and truly geeky. So I think I'll stick with the big light for winter commuting and use Mr. Sixteen

A couple other notes: JC Whitney also has a nice housing for the sealed beam bulb, stock number ZX133635N, also $14.99. It comes with a glass bulb that is too heavy for biking. I haven't found a source for the lightweight 25w halogen bulb other than Home Depot, which doesn't always have them.

I did notice that they are used in the emergency lights in my kids' school, with a logo that says "Emergi-lite," but I can't find those either.

I have found this gadget: http://www.nashbar.com/profile.cfm?c...eid=&pagename= allows me to mount almost any light almost anywhere on the bike, currently $3.49.

One more comment on the Optronics lights. My bike has disc brakes, but also has unused braze-ons for v-brakes. The Optronics lights screw right into them.

Some things were meant to be.

A popular way of doing a light around here is to use a halogen down lamp. These run at 12VDC and are available from any garden lighting or indoor lighting supplier. I used a steel can to make a helmet mount and use a 7.5 ah gel-cell lead acid battery which normally gets carried in my Camelback. My bulb is a Phillips energy saver 35W which is supposed to give about 45W worth of light. It is really good and outshines every store bought light I have seen. The battery lasts just over 2 hours so it is good enough for my evening rides in the forest. One detail was to get a headstone plug (odd name, I agree) with a spring clip so it could hold onto the bulb better.

I know most of the systems here are frame mounts which will be fine for street riding but my night rides are typically on single track or forest roads and a frame mount is rarely pointing where I need to be looking so I went with the helmet mount.

As a side note the helmet mount was really complex, made out of several large strips of velcro across one of the vents in the top of the helmet so I could get more surface area connected.

In the end I spent well under half the price of a new system and get better results. I have also made my own brake light/flasher unit for the back but that could be another post, really.

OK, here we go, at long last the pictures of my bike light.

Click here for the photos!

There are eight of them, each is 250K, so I can't post them here.

Cool light, eh? :)

Very cool jeff-o. Sleek looking, blends in with the bike. Battery looks nice and lightweight too. Are you using a current regulator like a buck puck, or a resistor to regulate the current to the LEDs?

Nah, I'm only using a resistor to limit current. It was tricky to get the right one in there too, since it didn't seem to follow ohm's law... or at least, the diode voltage drop was different than what I had calculated. In any case, I blew out two LEDs (the original chinese knockoffs that were in these flashlights) so I had to replace them with genuine Luxeon LEDs... It's probably better this way anyway, at least the LEDs are the same colour.

I still may add some ground FX LEDs as well, since as you can see from the night shot the bike isn't very visible except on the front and back.

Hmmm, buck current regulator, eh? I went the resistor route for simplicity's sake (it had to fit inside the body of one of the lights), but if I can find a clever way of properly regulating current, then I may do so.

I bought some 350 ma. and 1000 ma. Buck Pucks but haven't had time to test them yet. They are current regulators and they have only a 2 volt overhead if I remember correctly. I plan to make a headlight system using four 3 Watt Luxeons in series through a Buck Puck running off a 14.8V battery. You can simply short out one or two LEDs with a switch if you want high beam/low beam. Led Supply http://www.ledsupply.com/led-drivers-buckpuck.html has them from US$14.99 ea.

...head is feeling better from this week's crash (avoided L. Hook, ended up on a "field trip to the ER" for the day)...
DC, Please refresh my memory...are these 12V only or are they variable 12-24V?

These lights come with a 50W, 12V bulb which is too power-hungry for most biking applications, so you're going to want to change the bulb anyway. They take a MR16 bulb which is most common in 12V, but is also available in 24V (and sporadically in 6V). It's not really "variable" in the sense that you can run the same light off of different voltages, you pretty much have to run the bulb at its specified voltage.

Crash? Are you OK? How's the bike?

The bike is fine and sensation in my fingers returning. But the family is freaking and worried about future kooks... time to do some light upgrades for better size vis.

DC Yeah, I'd like a set that can run variable voltage 12-24...cuz the battery is 18V...I have a bag of bee hives from the last geek-light project. Maybe I'll forget the headlight for now and work on the side visability.

Trailhead makes a smart controller that allows you to run a 12v bulb at up to 20v, with 3 power levels, as well as flashing. It's $23.00.

http://www.trailheadlights.com/lightbrain/order.html

Does anyone have a good recommendation for a 12v battery that can handle a Luxeon headlight with multiple LEDs in the tail light and turn signals, and give runtimes of at least two hours? (Three to five would be better, but I'm not gonna get greedy) I would actually prefer it not to fit in my bottle cage; other than that, what've you got?