Make Your Bike Light Up for Style and Safety




About: depotdevoid is short for The Depot Devoid of Thought, the place where you go when you lo...

Here you will learn how to add a string of flashing multicolored LEDs to your bike for nighttime visibility and general awesomeness.

I made this for my daughter, slowly over the last couple of months. I've finally finished up, just in time for the Let it Glow contest.

The video should be working now, if it breaks again, please let me know!

***UPDATE 5/3/10:  Hey, if you make this instructable and post some pictures in the comments section, I'll give you a patch!***

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Step 1: Gather the Bits and Peices


1. Soldering iron. I like a 15 watt myself.
2. Tip tinner/cleaner and something to wipe the tip on. I know there are ways to tin your tip without buying this stuff, but it is just so darn simple, and you will be using it a lot as you get melted plastic all over your soldering iron.
3. Hot glue gun. Cheap and easy to find.
4. Exacto-type knife. Don't bother with a sharp new one, grab an old dull one you've got lying around. It will get duller as you go along.
5. Wire strippers. I don't have a decent pair, so I used my dull, dull exacto knife, some needle nosed pliers, and my teeth.
6. Wire cutters.
7. A surface area you don't mind getting all gunked up with blobs of solder, melted plastic, and hot glue, like my little soldering board my girlfriend keeps laughing at me about.


1. A bike. Any bike will do, but one that works would probably be best.
2. LEDs. I got mine from dealextreme, but if you don't want to wait 2-4 weeks you might try somewhere else.
3. Magnets (9mmx1mm disc neodymium). Dealextreme again.
4. Speaker wire. I picked up a couple of 25 foot spools at the dollar store. I liked it because it was flexible, and the wire is colored copper on one side and silver on the other. This will be important later on.
5. Low-temp hot glue sticks. You will use a LOT of these. Don't skimp, they're cheap and useful.
6. Solder. Duh.
7. Some sort of light up LED thingamajig that runs on 4.5 volts. I first tried using a bicycle taillight, but that didn't work with so many LEDs, then I think a fried the circuit board when I attached another battery (oh well, it was worth a shot). I then tried one of those flashing light-up coasters, but it didn't quite work right, and I broke it trying to make it work (damn these clumsy hands!). Finally, I ended up using a molecule ball I found in the toy aisle of the local supermarket. This turned out to be perfect for the job.
8. Electrical tape.
9. Cardboard. Found it in the recycle bin.
10. Zip ties. To hold it all together. I'd use duct tape, but I may need to take it off someday without leaving gooey duct tape gunk all over India's bike.

Once you've rounded all this up, set aside some time, 'cause this going to take a while! I probably could have cut the time I spent on this thing by two thirds if I'd ponied up the money for some LED christmas lights back when they were easily available. You'll see why in the next step . . .

Step 2: Prepare the Wire

This is easily the most time consuming step, where those already wired up christmas lights might have come in handy. My daughter India reads out loud to me every night as part of her homework, so this is what I did with my hands for a number of nights while I listened to her.

As I mentioned before, I used speaker wire because it is two bits of wire stuck together, and the wire is a different color on each side. Also, it's nicely flexible.

What you're going to want to do is grab your wire cutters and the speaker wire and go measure it against the bike. I planned on placing the batteries and circuitry under the seat, so I started there and measured out the wire, first from under the seat along the struts to both sides of the back tire, then from under the seat up along the main body of the bike, and finally from there up both sides of the handlebars, leaving some slack for turning.

With my daughter's bike, I ended up with wire sections that were 16" long for each side of the back wheel struts, 19" long for the body, and 13" long for each side of the handlebars. You will need to cut three wires for each of these sections, one for blue, one for red, and one for green. You could certainly add more, and my original intention was to string wires down the front fork and also on the lower part of the main body, but I soon decided that would take way too long.

Since the LEDs I have are clear until they're on, I ran a sharpie of the appropriate color along each of the wire sections, to keep track of which color would be going on which wire. This worked out quite well.

Next, you will want to take each of the sections and tape the three color coded wires together at one end. Take a black sharpie and mark a spot every 1.5-2 inches along the wires, alternating red-green-blue, red-green-blue so as to keep the LEDs evenly spaced along each section of wires.

After you've done this, grab your dull exacto and at each of the black marks on each section of wire, gently trim the coating off of the outer edge of the wire, until you've got a decent bit of metal exposed.

Now grab your soldering iron and run it along the exposed parts to melt away any plastic left over. This is probably bad for you, so do it in a well-ventilated area. When you run your hot soldering iron over the wire, you will both melt away any plastic you didn't scrape off, and at the same time, add a little bit of solder to the wire.

Once you've got the wire prepared, grab an LED and place one lead on each side of the wire , right where you've exposed the metal and added a little solder. Simply add a little more solder and stick your LED in place. Make sure you're keeping all the negatives on one side and the positives on the other!

Finally, when you've got all the LED's stuck in place and tested to make sure you've got connections, get out the old hot glue gun and go to town. As you can see from my horrible blurry pictures, I've gobbed up the glue all over the leads of the LEDs and along the wire to make sure everything is sturdy.

Step 3: Stick It All Together

Oh boy, more solder and hot glue!!!

This picture is old, like and idiot, I didn't take a good picture with the circuit from the molecule ball, but rather from the old light up coaster I ended up frying. Still, it all came down to pretty much the same thing.

Once each of the lengths of wire is ready, solder them together so that you'll have a red cord, a green, and a blue, each corresponding to the shape of the bike. Grab whatever flashy LED circuit board you've got and solder up the ends of the wires to the LEDs in the circuit, positive to positive and negative to negative.

Now turn it on! If everything lights up nicely, you've done it! You win the prize!! If not, DON'T do what I did. I'd already gummed everything up with hot glue, and just ended up frying the circuit board while I was trying to fix it. Once everything tests out okay, slather it all with the hot glue so nothing pulls loose. As you may have guessed, I really like the hot glue.

I ended up using an aligator clip (now thoroughly covered in hot glue) to hold down the pressure switch on the molecule ball circuit. If you don't follow the next step, you may want to replace the pressure switch with some sort of on/off switch.

Step 4: Optional: Battery Holder

You don't need to do this step, but you can if you'd like to use rechargeable batteries.

To skip this step, simply rely on the batteries that came with your molecule ball. No problem, I just don't know how long that's going to last running all these extra LEDs.

If you're going to do this, you'll need to solder a couple of wires to the positive and negative leads of the battery holder in your molecule ball circuit. Once you've done this, wrap the bare ends of the wires around some of your disc magnets and stick them on to the outside of the package somewhere. I made sure that the positive and negative wires had different magnetic poles facing outwards, one north and one south. I did the same thing with the homemade battery holder, so that there was no chance of connecting it backwards.

To build the battery holder, you'll need to measure out 3 AAA batteries and build a little box around them. You can see in the picture how to build a cut out which simply folds up to make a box. I wrapped it all up in electrical tape to keep it secure, and used those disc magnets to keep the lid closed. I used a combination of magnets and tin foil on the inside to connect the batteries in series, and then ran a wire from each end to the back side, where I had my polar aligned magnets.

With this set up, you can turn it on and off by simply taking the battery pack off, not to mention you can simply use rechargeable AAAs.

Step 5: Zip Ties, and You're Done!

Now you get to stick it all on the bike. You could use pretty much anything here, but I used zip ties because they are cheap, and unlike duct tape don't leave a messy residue when removed.

Once everything is put together, show it off! You'll be very noticeable on a dark street, and it looks awesome!

I hope you've all enjoyed this. This is my first instructable, so comments and suggestions are welcome. I know I probably should have take more pictures of the process, I'll do better next time! If you liked this, vote for me for the let it glow contest!

By the way, remember that if you make this instructable and post a picture in the comments, I'll give you a DIY patch!

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    21 Discussions


    i might add leds on my bike weel with my coils i will make so i ca have 1 wire going to the leds and the groud goes through the frame do not make this idear an instructable on this site

    1 reply

    10 years ago on Step 2

    I was doing this for a usb christmas tree..... I just ended up using the pre-wired series lights. (I was going for parallel, but it took for freaking ever.)

    1 reply

    Reply 10 years ago on Step 2

    Oh, I know. I REALLY wish I'd bought the LED lights around Christmas time. This was unbelievably time consuming.


    10 years ago on Introduction

    I believe that generic sodas tend to have the same if not better taste than the brand names. they're also usually quite cheaper. Walgreens brand cola (1 liter)- $1.04 Coke brand (16 fl. oz.)-$1.75 Making a joke about mastercard commercials- Priceless


    Reply 11 years ago on Introduction

    I did mention that in step 2. Of course, you'd still have to supply power to them, and I don't think you can run a string of christmas lights off of AAA's. I could be wrong.


    Reply 11 years ago on Introduction

    Yeah, I've seen those too. I think that I might have been able to adapt a string of LED christmas lights to the purpose, but those little 10-light strings wouldn't have been enough for what my goal here was. There are . . . hold on, I've got to go count. Okay, there are 45 lights on this setup, and they run off of three 1.2 volt rechargeable batteries. The 10 light strings you mention, if I recall correctly, use incandescent bulbs that run off of 2 D-cell batteries, so if I'd used those, I'd have had to cram 8-10 big fat batteries under the seat of my daughter's bike. But all of that is neither here nor there. You are right, in the sense that if I'd used christmas lights, I'd have saved myself some headache. What it really boils down to is that I wanted to have the bike flash in three colors, in a pretty and noticeable way, and also I had a whole bunch of speaker wire and a pile of LED's lying around, but no LED christmas lights to be seen.


    Reply 11 years ago on Introduction

    It might short, if it got really wet. All the guts of the thing are pretty well coated in hot glue, and the only exposed metal is the magnetic contact for the battery pack. The magnets are nickel plated, so they don't corrode easily. The battery pack itself isn't waterproofed, so if you got a good splash it would probably have some serious problems, but it lives under the bike seat, so it's pretty same from anything but splatter from the back tire. Also, one of the reasons for the removable battery pack is just so that you don't have to worry about rain. All of the sensitive components are sealed up, and the batteries just come right off.


    11 years ago on Introduction

    Ah, there's no feeling like that you get when you surprise a 6-year-old with something cool.


    Reply 11 years ago on Introduction

    Not sure. It's still running on the same set of rechargeable triple A's I originally installed, but that's probably a total of only a few hours of actual use.


    11 years ago on Introduction

    haha very nice :P you should have entered it one week earlier and entered the bike contest