In this, my first Instructable, I will show you how to use Cold Cathode lighting (Used in computer case mods) to make your bicycle VERY visible. It also adds a "cool" factor IMHO. If you commute to and from work, or ride at night / early morning, or just want the cool factor, this is for you. The tubes can be moved to other locations on your bike as needed or where space permits. Mounting the the unit to your bike is done with high powered magnets. If your bike is an alloy or composite frame, you may need to come up with a different method for mounting the system. Also, your tubes may be slightly different, but the setup is basically the same. Now for the legal stuff:


Ok with that outta the way, let's get started.

Step 1: Here's what you'll need

Here are the basic supplies you'll need to complete this project:

Thin CA and accelerator
Wire for battery pack 18 Gauge 2-Conductor
Magnets, General No. 341 (Two Packs !!)
Heat shrink sleeve, 4" width
Cold Cathode Tubes (color of your choice)
Female size N jack for battery pack Radio Shack 274-1576
Size N DC Power Plug Radio Shack 274-1573
AA Battery Holder 2 cell Radio Shack 270-382A
AA Battery holder 8 cell Radio Shack 270-0387
Assorted heat shrink sleeve Radio Shack 278-1627B
1/4 inch ID Expandable Sleeving
10 AA 2500Mah NiMH
12VDC Charger (Preferably smart charger listed)

If you purchase the smart charger shown, also add to the Radio Shack list, part # 23-445. This is what you will need to make the charger adapter for this battery pack. (See Photo below)

You'll also need some basic tools such as a pencil type soldering iron (Not the big Weller gun your dad has), rosin core or no clean solder, wire strippers / cutters, x-acto knife, Small screwdrivers, Hand Drills, helping hands or third hand (optional), Heat Gun (no your hair dryer will not work), patience, Common Sense and the will to proceed...

why would you use fragile and dangerous ccfl tubes when you can get led strips for 10 bucks and use a 9v battery<br>
As far as keeping the tubes on a bike with an alloy frame, you could use some zip ties on either end of the tube. It wouldn't be as portable as magnets but just an idea. Great instructable by the way!
Hey just to let everyone know, I had trouble recently with one tube going dim while the other was bright. After some troubleshooting, I discovered that the connectors in the powersupply box had cracked solder connections. Re soldering these connections has fixed the trouble for now but I think I need to find a better connector that can take the connect/disconnect cycles that this project goes thru. If you left the lights on your bike all the time, it is likely you will not experience the dim tube syndrome. Anyway I hope this helps. Take care, thanks for looking !!<br />
How much roughly did this cost? and are you really trusting magnets to hold them on to the frame i would zip tie also but im a belt and suspenders kinda guy
Roughly 40.00? I had some of the materials already. And as to the questions of the magnets, Yep they hold REALLY well!
This is a great instructable. Heres mine (unfortunately one of the tubes is uv, which was fun for looking at banknotes with but useless for lighting). Its also got velcro straps and stickyback velcro on frame and tubes so that the whole lot can be quickly removed so it doesnt get knicked/rained on/ you can then use them for something else.
I recently done this to my bike, but i used an old cordless drill batter that i took apart and i fitted everything into the bikes water bottle (partly for water proofing, but also so it wont get pinched when my bike is locked up) lol
Cool was it an actual water bottle? It is a shame in our world that we have to worry about things getting "pinched"....
I forgot to add this one too...<br/><br/><a href="http://www.instructables.com/id/Universal_bike_light_battery/">http://www.instructables.com/id/Universal_bike_light_battery/</a><br/><br/>Good instructable on a bigger battery for carrying in your water bottle cage..<br/>
hi yes, the battery i used was an old drill battery which i took apart and inside was a series of 8 large 1.2v batteries, they perfectly fitted into my bikes existing water bottle. all i needed was a small hole for the wires :)
for non magnetic frames you could always use zap straps, adhesive, or the modder's secret weapon, duct tape
Great ideas...Duck Tape...now a 1003 uses...
<strong>Thank You</strong> This is a great Instructable and I can see a lot of hard work went into this. You truly know how to lay out and execute a fine project. Thanks Again.<br/>kewrw28<br/>
No no... Thank you
If you don't have a Dremel I would highly recommend getting one. For this kind of project they are invaluable. Not only is it easier to shape and drill plastic, it's also very easy to notch PC board. They are wonderful tools to have and the lower models can be purchased for under $30.00. I have personally burned through 7 Dremels through my hobby rich life. I use them until the barrings die. I don't have a hydrolic press so it's kind of hard for me to change those. Something that lasts 4 years and is usefull for just about everything is well worth it. Trust me, you get one of them and you'll be impressed enough that you'll look for other things to use it for just to use it. They're addictive...
Yeah great idea !! on the first box I used a Dremmel w/ drum sander. Worked perfectly. Second one used the xacto.
i take it u cant bike in the rain with this otherwise awesome instructable?
Hi sorry for the delay. Yeah I think you could if you added RTV silicone to the tube ends. My inverter (power supply for the lites) rides under my saddle on the post which should protect it from most moisture. You need to check when you ride in the rain and see what is what. I recommend that you ride in the rain with the system OFF to see what you might have to change in terms of what gets really wet etc....
NiMH batteries don't indicate full charge with their voltage curve, so a thermistor is required to get a full charge (commercial NiMH batteries almost always have at least a third contact/wire because of this.) Without a thermistor, the charger either may overcharge the batteries (shortening their life, possibly destroying them,) or charge very conservatively, and not consistently fully charge them.
Can you site your source of information please? I have never seen a third wire on any NiMH cell, 'Course these are not commercial cells either and my charger uses peak detection of - delta V to determine full charge. What ever references you have are greatly appreciated !! Thanks
You found my source :P I have seen others that have similar recommendations. The reason for no third wire in cells is that the shells conduct heat pretty well, so the chargers can put the temperature sensing on the contacts. It's battery packs that generally have a third lead. Personally, I'd just risk it, now that you're as far in as you are. A good delta-V charger should be able to get pretty near full charge under most circumstances without overcharging. I'd try to not recharge a pack that's got more than 50% charge left in it though. The worst that will happen is you'll slowly kill the battery pack. Depending on how often you use it, that may take quite a while. If it does, just build a new pack for a thermal cutoff charger.
Ok I found a site here that goes over the thermal troubles with charging NiMH. and why -Delta V chargers can over charge...I don't think I have had that trouble but how would I know? Anyway, you can view the site here: <br/><br/><a rel="nofollow" href="http://www.powerstream.com/NiMH.htm">http://www.powerstream.com/NiMH.htm</a><br/><br/>I wonder what type of charger the Sanyo batteries need....<br/>
If you want a longer lasting battery solution, use LED tubes (aka meteor lights on computer case mod supplies websites), or even those new flexible LED strips that are weatherproofed
To whine - a little. Here is Straya - we have mostly useful and good road rules about lighting... All Sensible - All Standardised and All well thought out. WHITE only lamps and reflectors on the front, yellow lamps and reflectors on the sides of long vehicles and red lamps and reflectors at the back and this is for ALL vehicles. The only PLUS bicycles get is that they are permitted flashing rear and front lights. If you stick on BLUE - GREEN and or any other fab color... the cops pull you over and fine you. Unroadworthy - $120 on the spot fine - blah blah blah....... Still if WHITE means the front and RED means the back, at least it's all congruent. Sigh.
I've been pulled over while riding with green neons on my bike, because the cops wanted to know how to put neon lighting on their kids bikes. So your mileage may vary...
It's ok that you whine - a little...We may have the same laws here in California, I do not know. I should look into these (and if needed I can change to red or orange tubes...) and you should check your local laws to if you build this project. Thank you callmeshane for pointing this out.
You should use a small 12v lead acid battery instead of a ton of AAs. It would last longer and hold more power for its size.
Nah, a lead acid battery would be much heavier than some NiMh's which is important since it's pedal-powered.
How about a Li-ion battery? It would last longer, and be smaller and lighter.
Yeah just below here I addressed that. I would have LOVED to do that but the required extra circuitry for the care and feeding of Li-ion / poly was something (I do not know or take the time to figure out) how to deal with it. I think I'd get better performance outta the lights and lighter weight but I just did not want to futz with the extras involved.
No, a <strong>small</strong> lead acid battery. It would carry more power for its size and would already be 12 volts. You wouldnt have to wory about putting a ton of little batteries in series. And one again, I said <strong>small</strong>.<br/>
I like the idea but it would have to be really small, maybe 4Ah. I also toyed with using lithium polymer batteries but I'd need some type of cutoff circuitry to keep them from getting to low as you can ruin them if you drain them all the way...Perhaps I could get the cutoff circuit I need out of an old cell phone....
4Ah may not seem like alot, but it would almost be double the life of your current setup. It would aso be a little less complicated and easier to recharge than 10 NiMH batteries in series. It would also be cool if you could add a battery level indicator made from a micro and a small led bar graph.
But then it couldn't be in the contest. ;)
I know. I was just making a suggestion for anyone who wanted to do this project. ;-)
I like the magnetic attachment. Nice innovation. One thing to keep in mind is that the wires leading to and from the light tubes need to be properly strain relieved. You apply heat shrink after the wire leaves the tube, making it flex more right at the point where the wires leave the tube. On the<a rel="nofollow" href="http://www.rockthebike.com/lights/downlowglow">Down Low Glow</a> we use extra heat shrink that passes through a chrome cap into the light tube, stiffening this point. <br/>
Wow Great idea !! I'll continue the heat shrink into the tube to provide the needed strain relief. I had just thought about making them look nicer and not getting tangled around stuff. BTW LOVE The Choprical Fish, looking forward to seeing it and you in person sometime soon!!! Thanks!!
I completed a Green CCFL mod on my mountain bike about 3 months ago. You don't need to attach an extra AA holder. Each AA battery carries 1.5 volts. Wired in series (which the 8-AA holder does) creates 12 volts (1.5 * 8). Your extra two batteries are creating 14v, which still lights up the cold cathodes as the inverter can use anywhere from 12-20v. Just noting that it is an unnecessary step.<br/><br/>Also, as an aesthetic touch, use a 12 inch cold cathode for the central frame, and a 4&quot; cold cathode on your rear suspension.<br/>
Hm...Actually with NiMH batteries I measure 12.87VDC when charged. NiMH batteries are approx 1.2VDC per cell. When I was referring to adding another pack, it was to almost double the run time due to the increase in current. I really like your 4" CCFL idea and I do have a shorter tube that I was thinking of using on the small part of my frame above the crank housing.... Thank you to all who have commented !!
Figured I would show you a picture of my bike so you can see the effect. I've also create my own front light of my own design (10 320,000mcd White 40 degree LEDs).
NICE!! Did you do the tail light too? Does it have turn signals? How did you attach your tubes? Talk about being seen!! No worries when your on a night ride!! Very cool...Thank you for sharing. I think I need more lites....
Hey I forgot to ask....Have you done an Instructable on your headlight? Looks way bright. I'd like to have one for my bike. I have a bell light with high and low and LED light but I want one that is super bright.
I have not done a instructable on my headlight, I really wish I had when I built the thing. The picture was taken the day those batteries died, so its much more dim that the real thing - you can't even look into it at night. It's built with 10 10mm 40 degree 320kmcd LEDs that have been wired to 4 AA batteries.<br/><br/>I have a $1,800 mountain bike that I take down the mountain trails here in California. As I don't want my CCFLs to break if I crash/land on a tree, the cold cathodes have been glued inside of <a rel="nofollow" href="http://www.tapplastics.com/shop/product.php?pid=276&">1/8&quot; TAP Plastics tubes</a>. The cathodes are glued by their ends to the cut tube.<br/><br/>Tail-light was purchased for $10, no turn signals, and every time I ride my bike through the city at night cars honk, people yell their appreciation, and the whole road is lit up.<br/>
Also, excellent instructable. It is very detailed with clean and easy methods of putting the system together. The use of heat shrinking is well done.
Superb outcome on this project, good idea I think. But can anyone vouch for the legality of such a thing? If I remember right, there are laws against certain colour lights due to the (in this case remote) possibility of being mistaken for a siren. I could be completely misinformed on that however. :D
dude i am so doing this... as soon as i finish my other projects
That is really good!
Any chance you could add some more photos.......just kidding looks like a very good instructable.
this has already been done, a few times. but this explains it in more detail. i feel bad for not getting mine posted. :-(

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