Introduction: GlowHacker Bike Lights Workshop

About: Former Artist in Residence at Instructables, currently Hacker Advocate at Hackster. Cofounder of ProtoTank, a hardware prototyping startup. FIRST kid (rock on, team 677!). Former board member at AHA (Ann Arbor…

There are too many intelligent, talented people riding around without any lights, like total idiots (a.k.a. "darkwads"). To help change this, I've been running a workshop called GlowHacker, which puts TRON-worthy light strips on your awesome bike.

They're durable! These bad boys stand up to a lot of smashing, as well as rain, mud, heat, and even playa dust.

They're cheap! The basic workshop doesn't teach anything too fancy, but is still hella fun and gives a great effect!

They're versatile! Each participant so far has created a different look, even with just a few LEDs. These become a visual signature as you explore the city at night. And they can be applied to bikes, skateboards (check out my Glowmobile up there), wheelchairs, Segways...

They're pretty theft-proof. I won't lie: one person has had his ripped off, literally. Which is incomprehensible, as they have basically no retail value and are glued to the bike frame. But this is much less of a worry than with detachable lights, and much cheaper than heavy-duty antitheft lights.

They're PRETTY! I mean, just... yeah.


Thanks to Snail and Vivian, of Double Union, for playtesting this!

Step 1: Bill O' Materials

The typical workshop covers a taillight or handlebar set, and this Instructable will specifically talk about taillights (though you can easily adapt it).

Shared materials

  • Hot glue gun and appropriately-sized glue sticks
    • Hot glue is the best adhesive I've found for this. It sticks to bike varnish better than epoxy does, and if you need to make a repair, it's relatively easy to peel off. Epoxy is a nightmare!
  • Zip ties (various colors) (long ones!)
  • Heat shrink tubing (various colors)
  • Torch or heat gun for heat-shrink
  • Solder wire
  • Sharpie

Per person

  • Soldering iron
  • Wire strippers and side cutters
  • 5 feet of solid-core dual wire: Solid-core wire is more rigid, which helps it stay in place and bend less on the bike, giving it more durability. You can get speaker or motor cable, which is 2 cables stuck together, usually with one demarcated as ground.
  • 3 strips of 5050 RGB LEDs with epoxy coating (a.k.a. fitty-fitties): two 5-section strips and one 2-section strip.
    • The LED strips are divided up into sections of 3 LEDs each, with copper pads separating the sections.
    • Each section is 2", or 5cm, long.
  • 1 x 9V battery
    • The LEDs are designed to run on 12V. However, they shine mighty bright on a fresh 9V. If you want full-white lights, though, you'll need to use 8 AA batteries or a lantern battery.
  • 1 x 9V connector (or holder for another type of battery)
  • 2 x toggle switches (one multi-pole for power, one for colors)
    • Double-pole, single-throw should suffice for power. For any section that switches between colors, you'll want a single-pole, double-throw switch.

The materials are intentionally generic, and can be obtained from Amazon, Radio Shack, and/or local electronics or art stores.

Step 2: Design

Once you've got your kit, answer these questions:

Which parts of the bike do you want to light up? Hold up the LED strips to your bike, and see how many 2" sections will fit in the space you have. A few tips:

  • Flat areas are best, or wide tubes. You can get away with smaller tubes if you zip-tie your lights on, in addition to gluing them.
  • Make it visible! First, make sure your back fork is lit. Then, cover the front. Finally, go crazy and plaster lightbeams all over your frame!! The more, the better!!!!

What sorts of colors do you want? Red is traditional for the back, and will make you understandable to traffic. Technically, blue light is reserved for emergency forces, but I've never been hassled (and I doubt anybody suspects that I'm a really skinny ambulance).

Battery life is a consideration here. Red lasts the longest, then green, then blue. Supplying power to multiple colors at a time (for example, to get orange or purple) will slurp up more.

You can also add switchable colors (as we'll see later), so bear that in mind!


  • Don't have LED strip ends butting up against the frame. You'll need to solder to those places. You can sometimes get away with curving the strip around to the side, or simply attaching it at an angle that allows it to be seen but isn't interfered with by structural components.
  • Make sure they don't shine up into your eyes! (This mainly goes for stuff on the handlebars and middle tube.)
  • Keep LED strips and cables out of the way of kicking feet, or anywhere they'd get routinely smashed -- although these can handle a lot of punishment, you probably don't want to push it.

Handlebars, post rings, seat post, back forks (facing back or at 45º), front forks (on the front or sides), ground effect lights: these are all excellent ways to light up your steed.

Step 3: Cut Pieces to Fit

Hold the LED strips up to your bike. (It can be useful to have a friend help for this step.)

If any pieces won't fit, trim them down, section-by-section. The 3-LED sections are separated by sets of four copper pads. Cut across the center of the copper pads - there is a line down the middle to help gauge this. (You can use most wire cutters to do this, and scissors should also work.)

Once your LED strips are the right length, hold up the piece of speaker cable and cut sections to connect the LED strips, battery, and switch.

  • Tack on a little extra wire length - maybe 1/2" - to give you room for good solder connections.
  • Stick as close to the frame as possible. If you can route behind or between parts of the frame, do it! This will help keep your cables from catching on things.
  • For handlebar lights, you'll be routing cable past a pivot point. Before cutting this cable to length, hold or lightly tape it in place, and make sure that you can turn the handlebars as far as possible without straining the cable. If possible, when you're done, zip-tie the wire to your brake cable to minimize its chances of being yanked on. Pivot points are common failure points, depending on how much the wire gets flexed back and forth.

Step 4: Lay Out the Circuit

Lay out your circuit on the table:

  • Take the two longer strips and put them side-by-side, with the stripped ends facing left. They may curl up a bit. Don't worry about it. This means you got some from the center of the roll! (If this happens, just put something on top of the piece to weight it down flat. It makes soldering much easier!)
    • Note whether the "12V" label is at the top or the bottom.
  • Somewhere off to the left, add your center 2-section LED strip. Make sure that the "12V" labeled pad is on the same side (top or bottom) as with your long strips.
  • Next, lay out your cables between them. The LED strips only need to be connected on one end.
    • Use consistent cable placement: white (or red) to power, black to each color rail. Or, if you have multicolored cable, use red cable to connect "R" pads to "R" pads, and so forth.
    • Put the long cables next to the long LED strips.
    • Lay out the Y-splice cables between these and the short LED strip.
  • Lay down the cable that joins the short LED strip to the battery cables.
  • Put your power switch between this cable and the red (power) battery cable.

The Y-Splice

In order to power both sides of the fork, you'll need to split your circuit into an inverse Y. See the pictures for an example of how to do that.

If you have more cables (because you're using more than one RGB color), just make sure that each color rail stays continuous: the "R" line from the first LED strip feeds into the "R" pad on each of the strips that follow it.

For the experienced: Since your cables will be side-by-side, it can be a little easier to solder them together if you "bevel" the cuts. For example, assume that your 12V line is on the right, with colors to the left. So, cut the 12V cable a little longer on the left strip, and a little shorter on the right. Then, do the opposite for the color line: a little shorter on the left, longer on the right. Now, you can cross them over each other without pulling on the cables.

Strip the components:

  • LED strips:
    • Wedge your fingernail (or a knife, assuming you understand basic safety measures) between the clear epoxy and the copper pads on the LED strip.
    • Pry them apart gently, being careful not to damage the circuit, or yourself.
    • Then, trim off the loose epoxy coating with your clippers.
    • Make sure you uncover the copper pads completely (unless you just can't get enough of that burning silicone smell).
  • Cables:
    • Wherever the cable attaches to LEDs, strip it about 2mm, or a little less than 1/8".
    • Wherever cable attaches to cable, strip it a little longer.

Step 5: Solder It Up!

Woooo! All the boring stuff is over. Now, let's play with some heat.

Grab a helping hand to hold the hot metal for you.

Tin each connection first: every copper solder pad that you'll be using ("12V" and "R"), and every cable end.

Then, hold 'em together and apply heat. You shouldn't need to add much, if any, extra solder.

When soldering cables:

  • Lay them end-to-end and then overlap them a little, rather than joining the very ends together.
  • Only overlay them as far as the bare wire goes (see image with the 9V battery). This will make a slightly better seal against the weather, and it also looks nicer.
  • Cut a piece of heat-shrink tubing that's at least 1/4" longer than your joint, and slip it over the joint BEFORE you solder.
    • Make sure that it completely covers the joint.
    • Then, slide it down one of the cables, out of the way and out of heat range.
    • Solder your connection, let it cool a little, then slide the heat-shrink over it and apply heat with a mini-torch or heat gun. (In a pinch, you can run a soldering iron over the tube, but that is NOT recommended as it smells and screws up the iron -- besides being less effective.)

From time to time, hold the circuit up against the bike again, to double-check that everything will fit correctly.

From time to time, grab your battery and test the sections you've soldered, to make sure that everything works.

Step 6: Try It on for Size, Glue It Up, Add Power... and Get Out There!

The LED strips come with adhesive backing. Remove the sticker backing on them (taking care not to damage the circuit strip itself), and stick them in place. Now's your last chance to make any adjustments necessary! Make sure that everything fits well, and nothing curves out into the void or is stretched too tight.

Wherever you've got a join on the end of an LED strip, just drown that sucker in hot glue. Make a nice little bead, to weatherproof the joint and also connect the strip end to the bike. Add extra glue anywhere that makes sense -- for example, if you're using a Y-joint to split the cable for handlebar lights, glue that joint to the center of the bar and cover it up.

If you're attaching to a narrow tube on the bike, with a fairly curved surface, jam the nose of the glue gun under the cantilevered edge of the strip and fill in the gap a bit.

And in any place that's structurally weak, add zip-ties. You don't usually need a lot -- but they're great for:

  • Securing cables to the frame (wherever possible!)
  • Anchoring LED strip to narrow tubes
  • Anywhere anything might get caught or tugged on. Zip-tie it down to something structural!
  • Going to the desert, since the hot glue may start to fail in extreme heat.

Attach the switch and batteries

I use zip-ties to attach the switch and batteries underneath the seat (see diagram). This provides protection from the elements, as well as random bashing.

Two zip-ties go on each battery (I have two, for the front and back circuits). I don't protect the battery connections, and have never had issues with the connections shorting -- but I'm designing a case to protect both these and the switch.

The switch goes at the front of the seat, where you can easily reach it while you're riding. Yes, it looks a bit like you're grabbing yourself. No, nobody cares. :)

Step 7: Appendix A: Colors and Power

So! You want badass shiny colors on your bike. Your bike is a unique individual! Here are some notes on that.


I always recommend red for the taillight. There are a couple of reasons for this:

  • It's a standard "back of vehicle" color that drivers are acclimated to;
  • It takes the least power, so it will last long, and this is the most important light for not getting hit in the city.

Mixing different colors

Since we're dealing with light, the colors are additive. You have red, green, and blue. So, you can get other colors by combining them (which will, of course, take extra power):

  • Yellow(ish) = red + green
  • Purple = red + blue
  • Cyan = green + blue
  • White = all colors

Switchable colors

You can also make a single stretch of light strips switchable - so that they can be green or red, for example, based on your whims (TURBO MODE BLUE!). See Appendix C: Switches and Circuits


Different colors take different amounts of power. Remember the visible light spectrum? The higher the frequency, the more power it eats. So, red takes the least power, green a little more, and blue the most. That said, red is also the dimmest -- though it's PLENTY bright at night.

You can put different colors in a single circuit, but as the battery wears down, the power will travel by the path of least resistance. That means that the lower-power colors will suck the energy*, and blue will die first, then green, and finally red. For this reason (plus the safety reason for the taillights), I generally put different colors on separate circuits.

Of course, a section with fewer lights last longer on a single battery. I ride every day, perhaps an hour a day on average, and mine will go for at least a month on a fresh 9V. The red back lights are extremely important when you're biking in traffic, and this small circuit in low-power colors will last a good long while on its own battery. As a side note, you'll notice them fading long before they go out.

* If put in parallel with higher-power colors. See Appendix C: Switches and Circuits

Remote-control insanity lights

If you've bought your own LEDs off Amazon or somesuch, you can get 5m for about $20, and they will come with a blocky white driver module and remote control. This is super awesome, and will also run off of 9V (though, again, some colors will be unavailable). It's a little less certain to be durable, and in order to keep workshops affordable, I usually make this an option for $10 above the regular materials cost.

Just make sure that the IR receiver (the little black plastic thing sticking out of the driver block) protrudes from under your seat, so that you can hit it with the remote. And remember to bring your remote with you -- or add a switch to the circuit, to turn them on/off. (They will remember the mode that was previously set.)

I also can't vouch for this method being as weatherproof, though they did survive a trip to the desert.

Finally, make sure to solder all four connections on your LED strips (+12V, R, G, B) if you want to have the full range available.

See the video below for a (shaky, blurry) idea of how it can look!

Step 8: Appendix B: Sticking Stuff to Stuff

Types of joins:

  • Cable to cable:
    • Strip the ends 1/4"
    • Tin the ends
    • Overlap the tinned ends
    • Add heat-shrink tubing (enough to amply cover the joint)
    • Solder the join
    • Shrink the heat-shrink over the join
  • Cable to LED strip:
    • Strip cable ends short
    • Remove epoxy from LEDs' copper pads
    • Tin the ends
    • ...Yep
  • Cable to switch:
    • Strip cable ends 1/4"
    • Don't tin them yet! Thread them through the holes in the switch contacts, and bend 'em back so they stay in place for now.
    • Then, apply solder to the entire joint. Try to make it somewhat structural, as well as getting a good electrical connection: cover the entire connection.
    • Slather it with hot glue, all over, baby. This is for structural support as well as weatherproofing.
  • LED strip to LEDs (patch -- see images):
    • This is a weird one!
    • Use this when you've got your lights on your bike, and can't easily remove/replace them. Or if one LED or section is faulty, and you only want to replace a small bit.
    • Strip about 1/2" of solid-core cable.
    • Cut off teeny bits of bare copper wire, about 1/4" each.
    • Tin the pads you want to connect, on either side of the connection.
    • Grab a little bare copper piece with tweezers, and solder it to one side, sticking out enough so you'll be able to attach it on the other side as well. Repeat for each pad that needs to be connected.
    • Lay the two LED strips down so the ends butt up against each other. (You may need to weight the strips down.) Make sure that each little copper bit sticks out onto the opposite tinned pad. It should be almost horizontal.
    • Heat up the whole shebang: the pad on one side, the little bit of copper, and the corresponding pad on the other side. Melt it all together! Homogenize it, make it one with itself.
    • Smother it in hot-glue!!!

Attaching stuff to the bike:

Hot glue for attaching LEDs to the bike, and protecting/weatherproofing any solder joints on the end of LED strips.

Zip-ties for attaching cables to structural components, reinforcing areas of weak join, etc.

Epoxy NEVER!

Step 9: Appendix C: Types of Circuits

Useful info for doing this stuff! You won't be an electrical engineer after this, but hopefully, you'll learn a thing or two.

Anytime you're adding switches into the circuit, attach the battery cable to the center pin on the switch.

Changing colors on your bike

Maybe your bike gains different powers in GREEN MODE vs. RED MODE. Maybe you want to use rad blue lights in the city, and low-power red for long trips. To add colors, you'll need one extra switch. (If you want more than two colors, you'll need a dial instead.)

Control the power with one switch:

  • The red (positive) battery lead goes to the center pin on one switch.
  • Then, connect another length of cable to one of the outer pins. Solder this to the "12V+" rail on your LEDs.

The colors go on another switch:

  • Solder the black battery lead (ground) to the center pin on your second switch.
  • Connect a cable from one of the outer pins to one or two color rails.
  • Solder another cable from the other outer pin to the remaining color rail(s).

Series vs. Parallel

So! You're gonna be hooking up cables in two different ways: the two long 5-strips are wired parallel with each other, and they are in series with the little 2-strip.

Power has to go through the 2-strip to get to the other two. Power gets split between things that are in parallel. If you put low-power red in parallel with blue (which requires lots of power), the power will go through the path of least resistance -- so blue will be dimmer. Better to have it on a separate circuit.

On the other hand, you can put different colors in series with each other. I haven't done this on my bike, but in theory, you would hook it up this way:

Ground --> "R" rail into strip 1 --> leds --> "R" rail out of strip 1 --> cable --> "G" rail into strip 2 --> leds --> "G" rail out of strip 2 --> cable --> "B" rail into strip 3... etc.

Tangent: describing switches... Be patient with me for a minute here. The little back-and-forth switches you've seen so far are single-pole, double-throw switches. That means there's a single on/off option being controlled, and you can connect the center pin to either of two outside pins.

In the case of the power switch, you're really just using it as a single-pole, single-throw switch: Because there's nothing soldered to the second outer terminal, the possible positions are "open circuit" (i.e., not connected) and "closed circuit" (power is flowing).

For switching between colors, you're using its full potential as a single-pole, dual-throw switch: The center pin is connecting to either of two outer pins, which control different colors.

I've also got a picture up there of a big rocker switch. It controls three circuits at once, and can connect the center pin (in each row) to either of two outer pins. So, it's a triple-pole, double-throw switch. I use one of these on my bike. That's because I have two 9V batteries: separate power sources for the handlebars / ground-effect lights vs. the taillight. They're completely separate circuits, but I can turn the whole bike on or off with a single switch. It's really convenient!

Step 10: Appendix D: Troubleshooting

Try to avoid sharp bends and flex points in your cables. (With handlebars, this is kind of unavoidable, but can be mitigated by anchoring those wires to a brake cable.)

if you have flickers, make sure you're fully heating up both pieces of the join, as well as the solder, when attaching things together. Try wiggling different cables, while holding everything else still, to isolate the failure.

The same goes for switches: make sure that you have solid connections.

Step 11: Appendix E: Running the Workshop


If you're using these directions as they currently stand, allot 4-5 hours for adults. (That's why I'm making an instructable...)

It may help to make it an all-afternoon thing, arrange for a food break (hunger + lots of soldering --> cranky humans!)


You might want to add a celebratory ride when you're done! People will likely be tired and want to get home, but you could take a group trip to a restaurant. It could be great "bonding time" / decompression... plus, teaching this is hard work! And as a reward, you get to lead a kickass TRON BIKE GANG through the streets of the city!

You can combine this workshop with one for security: bring an engraver and put identifying marks on bike parts. Coat with a clear sealant immediately; I'm seeing a little corrosion on mine, after using clear nail polish. There are spray-on solutions for this.

I usually charge $15 per person for the workshop, to cover materials and keep it affordable -- $25 if someone wants to use the remote-controlled driver block.

Step 12: Appendix F: Be Prepared!

While you're waiting for your LEDs to arrive, or for your workshop date, or to set aside time for this – get a head start on your design! This will make the workshop go MUCH faster for you, and you can finish the hands-on work in one go. Plus, you can dream about it while you're riding, and you'll have a more mature (read: awesome) design.

Seriously, lots of people hit sand at this stage, having to be creative at a scheduled event. Save us all some time and have a plan!

First, check out Step 2 for some ideas. See my notes above for an example design.

Now, take a measuring device to your bike. The LEDs can be cut in increments of 2" (a segment of 3 LEDs). How many segments are you going to have in each spot? If you're doing this for a workshop, find out how much LED strip you'll have available, and decide how to make the best use of your kit.

Will you need extra switches (for color-changing designs)? Do you want your lights to be remote-controlled? Do you want a special "stealth mode" that saves battery, and shows a lower profile, while keeping you safe? (Always put a bit of light on the back fork!) Plan these things out in advance, and make sure that the materials are available.

When the day comes, you'll be ready to rock. And roll, I guess. Both of those things. :D

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