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"Cypress Gardens" Fl.
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685 Posts
Discussion Starter · #1 · (Edited)
Hey guys, this is in response to several RBR members who have displayed an interest in
building a cheap, very bright, bike light for those late night fast rides. I've spent months researching this project because I needed a good, bright bike light for my 14 mile commute to work, something that is more durable and just as effective as those high dollar $300 - $400 HID lights out on the market. I built mine out of simple pvc pipe, for less than $50 bucks, powered by a 5 aH Sealed Lead Acid battery, and it will 'light up' the road almost like a motorcycle headlight. The light is very bright and will provide more than enough projected light for 20 mph night rides lasting two hours or better. Hopefully some of you can benefit from this, as I certainly have. It is simple, elegant, and cheap, and will 'light up' a stop sign from 200 feet with plenty of periphial visibility. I've been using this for several months now in almost total darkness, and people have said they thought I was a slow moving motorcycle. The light is 'significantly' brighter than my 'cateye' EL-300 light I was using, and is much safer. In fact my wife said that from a mile away, the only reason she knew it was me, and not a motorcycle, was the light wavered from side to side from me pedaling. (I thought that was pretty cool)

All the parts you need, except for the battery, are available from 'Lowes' or 'Home Depot', in the outdoor lighting section, and since it's made out of pvc pipe, is very lightweight and near indestructable.

~To start with you'll need a "GE" or "Sylvania" MR-16 12v 20-watt halogen bulb/reflector with glass cover preferrably from 'Lowes', as they seem to have a better selection. The halogen bulb/reflector with the glass lens is meant for outdoor lighting, and is a sealed unit that comes in a cardboard bubble pack and costs about $7 bucks. They come in several beam patterns from spot to flood, but what seems to work good for me is the 17 deg. spot beam. (Good beam projection with sufficient periphial illumination) The code number on the package should be "ESX"
 

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Downhill Juggernaut
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1,668 Posts
I'm liking this already... I think I've got one of those bulbs at the house. Just sitting there doing nothing.

Hope you can finish these instructions tonight... This will give me something to do tomorrow.
 

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"Cypress Gardens" Fl.
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685 Posts
Discussion Starter · #3 ·
Part 2

The "GE" or "Sylvania" MR-16 halogen bulb/reflector is 2" in diameter and uses a two pin connector or 'socket' that pushes onto the pins on the rear of the bulb. You can buy these two-pin connectors (GU 5.5) on-line at www.harringtonlights.com for about $3 or $4 bucks and have 5" heavy duty lead wires coming out of it so you can wire it to an automotive two-way switch and then to your battery.

Since I was in an all fired up hurry to build this light, I bought an outdoor "Malibu Yard Light" at 'Lowes' for $9 bucks and pirated the two pin connector, along with the heavy duty glass cover lens. Everything else I discarded. Below is a pic of the "Malibu Yard Light".
 

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"Cypress Gardens" Fl.
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685 Posts
Discussion Starter · #4 ·
Part 3

Please make sure the MR-16 bulb/reflector is 12 volt, cuz they also make it in 110 volt from 20 watts to 75 watts. You need a 12v 20-watt MR-16. Thats what I use and it's great. The bi-pin connector you need comes with the 'Malibu Yard Light", and is about the size of a nickle. It has two holes in it that pushes onto the bi-pins on the back of the bulb. Once you push it on the two pins I would'nt worry about it loosening, or slipping off because it's pretty sturdy.

O.K.......So far we got the MR-16 halogen bulb/reflector with cover glass that is a sealed unit, and we have a bi-pin connector that pushes onto the back of it. Right??

~Next you are going to need a pvc compression union (pictured below), but you will only need the inner part of it. I believe it all comes in one assembly, but you can look around.
The part that you need in the picture is the middle one. It's the inner sleeve, and the inside diameter of it is damn close to the diameter of the MR-16 bulb. The outside diameter of the inner sleeve is 2 1/4-in., and is the one with the flange on it. That particular little gem is the main housing you'll need to set your MR-16 right inside it. It has a little lip, or bevel at the end that your bulb will seat up against perfectly. But first you'll have to use a dremel tool, or drill motor to sand the inside of that sleeve enough for your bulb to gently slip inside of it and seat against the beveled edge. Once you see how the bulb seats against the inside beveled edge you'll know why I call it the little gem. It's perfect!!

I used a sanding drum on my dremel tool, and it worked great. Just sand off enough for the MR-16 bulb to slip inside the pvc pipe or sleeve, and it will rest against the beveled end.

To help clarify the size of the parts in the compression union, the big outer ring that looks to be tightened by hand is 3 1/4 in. in diameter. The outer ring is threaded on the inside, but you wont need it. The one you want is the inner sleeve, with the flange. Thats the little gem.

~o.k. kids, thats enough for today. I have to get ready for my night ride to work. Tomorrow we will cover more of this project.
 

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"Cypress Gardens" Fl.
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685 Posts
Discussion Starter · #5 ·
Here is a few more pics of the inner sleeve, along with the finished project. Remember, the inside of that sleeve has to be sanded a little so the MR-16 bulb will slip right into it and seat against the beveled edge.
 

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"It's alive!"
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1,454 Posts
croswell1 said:
Here is a few more pics of the inner sleeve, along with the finished project. Remember, the inside of that sleeve has to be sanded a little so the MR-16 bulb will slip right into it and seat against the beveled edge.
This is just too cool for school. Thanks!! I'm looking forward to future installments.
 

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Resident Curmudgeon
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11,981 Posts
Thanks Croswell. Great info, & the pics help a lot, too. I'm looking forward to more.
 

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Rollin' Stones
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2,560 Posts
Awesome!

This is the most interesting thread ever. Please keep up with the build!
 

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"Cypress Gardens" Fl.
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685 Posts
Discussion Starter · #10 ·
Part 4

Good morning children.

The correct identification number for the bi-pin ceramic connector you need is "GX 5.3" if you opt to get it on-line from www.harringtonlights.com
They also carry a multitude of MR-16 12v bulb/reflector sealed units with cover glass. If you buy the "Malibu Yard Light" from 'Lowes' it will come with it. Just pull the connector off the bulb in the yard light, take out the heavy duty glass lens, and discard the rest. Below is a pic of the connector. The two small holes in the middle push right on the bi-pins at the rear of the halogen bulb and stays secured pretty good. Dont worry about polarity, just make sure one of the wires on the connector is ground, and mark it as such. That wire goes straight to neg. on the SLA battery. The other wire is of course positive, and that will be the one you wire into the automotive switch. I'll post complete schematics later on.
 

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"Cypress Gardens" Fl.
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685 Posts
Discussion Starter · #11 ·
Part 4.............continued

O.K.,......Once the inside of the inner sleeve has been sanded enough for your MR-16 bulb to slide into it and seat against the beveled edge, you will need a tube of "Clear RTV Silicone Adhesive" available at any auto parts store, Lowes, Wal-Mart etc. What you want to do is lay down a heavy bead of silicone adhesive inside the pvc sleeve, right there at the beveled edge. While the adhesive is still tacky, clean up the glass lens from the Malibu yard light and push it inside the pvc sleeve until it's firmly against the lip, or beveled edge. Dont worry about the adhesive oozing out on the glass lens right now. You want to firmly bed the glass lens in the adhesive, because when it dries it will be waterproof to a factor of ten. Hail, sleet, snow, and rain wont faze it because of the thickness of the glass lens and the bed of adhesive it's laying in.

After the silicone dries use an x-acto knife to trim away the excess glue on the outside of the lens. Just scribe the knife tip around the outside bevel and cut the excess away. If you really made a mess on the outer glass use a single edge razor to scrape it clean. Works great ~ btw, just make sure the inside of the lens is sqeaky clean before you slip the MR-16 bulb inside the sleeve up against the glass. ~note~ the heat generated from the 20-watt bulb will not effect the silicone in the least, nor will it effect the pvc pipe. It may get a little warm, especially if you're still, but it will be just fine.

~ After all that's done, push your MR-16 bulb inside the sleeve until it rests against the glass lens.

~ next you will need to cut a 3/4 in. wide section of pipe off the end of some other pvc pipe that is preferably the same O.D of your sleeve. You will then cut a 1" section out of it until it resembles a "C". (see pics below) The idea is to compress the pvc ring until it slips inside the sleeve, then you push it up against the back of the reflector you installed. This will secure the bulb/reflector to keep it from jarring loose once everything is together.

~ Once the glass lens is glued in, and the bulb/reflector installed with the pvc ring snugged up against it, you will need to tack glue the pvc ring in place with silicone adhesive. All this is done to keep the bulb from jarring loose and rattling around inside the sleeve. Look at the pics below and you'll get the idea.
 

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just ride your bike
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518 Posts
That's awesome; once you're finished with the explanation I'll probably be off to Lowes to build my own. I'm curious though; how much does the light unit and your battery weigh? I'd be using this for mountain biking, so it would be helmet mounted with the battery in my Camelbak.
 

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"Cypress Gardens" Fl.
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685 Posts
Discussion Starter · #14 ·
desurfer said:
That's awesome; once you're finished with the explanation I'll probably be off to Lowes to build my own. I'm curious though; how much does the light unit and your battery weigh? I'd be using this for mountain biking, so it would be helmet mounted with the battery in my Camelbak.
The pvc bike light is very lightweight. I'd doubt you would even noice it strapped to a helmet. The 5aH sealed lead acid battery I use goes into my back pack and plugs into the light via two connector trailer harness. The battery weighs 4 lbs, and will give you over two hours run time for a 20-watt light. Hopefully no one will assemble this until I'm finished explaining everything. I have several different options to show.
 

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Downhill Juggernaut
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1,668 Posts
Ok, I gotta admit I got a little impatient. I went to Lowe's today to get some of the stuff I saw. Unfortunately the only Union joints offered here are ribbed on the outer surfaces, which means the rest of the body wouldn't work right. So I did a little messing around and came up with a solution that looks similar enough. A 2" to 1.5" reducer coupling, a 1.5" end cap and a 2 X 1.5" bushing for the crown bezel. I joined the reducer coupling to the end cap with some 1.5" hot tub tubing. Waterproof and nice and sticky. Figured I would need to be able to take it apart to change the bulb out someday.

I haven't done any of the electronics or switches yet. I'm waiting to see how you did yours, but I have a pretty good idea already. Don't keep me in suspense too long.

Oh, did you give any thought to a 6V battery? I don't know how that would affect the lights capability since I'm no electrical guru by any means. That would cut the weight of that battery by about 60%. Of course, if it cut output that much then it's not worth it. I'm more or less just thinking out loud at this point.

I'm also eager to see your mounting brackets as well.

Here's a pic of my work thus far:
 

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Downhill Juggernaut
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1,668 Posts
Forgot to add, I added the computer to give it a sense of scale...
 

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Downhill Juggernaut
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1,668 Posts
croswell1 said:
Hopefully no one will assemble this until I'm finished explaining everything. I have several different options to show.
DOH!

Luckily nothing is glued yet.
 

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"Cypress Gardens" Fl.
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685 Posts
Discussion Starter · #18 ·
Have to admit thats not bad, Chris. In the world of pvc the possibilities are endless. Almost anything would work as long as it could accept an mr-16 bulb and look halfway decent. The housing i've been showing seems near perfect because of the beveled lip the bulb can seat against. I'm no bike scientist, but I am handy with tools, and I can even ride my bike and chew gum at the same time. LOL
 

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"Cypress Gardens" Fl.
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685 Posts
Discussion Starter · #19 ·
Check out these pictures here. This is the one that will replace the light that's now on my bike. Much simpler to build, more streamlined, and looks great, IMO.

The last pic that shows the black line is where you grind down to, to really streamline the housing. In fact the first light I built was just like that and it was great. The only reason I built the one with the removeable face was to access the bulb and the internals. That one was a bit more complicated to construct. The one I'm showing the how-to on is the streamlined one, which is totally sealed and uber waterproof.
 

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"Cypress Gardens" Fl.
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685 Posts
Discussion Starter · #20 ·
O.K. guys, here is the wiring diagram I used, along with some more pics. Do a google search for Do It Yourself bike lights and you'll get a wealth on info.
 
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