Introduction: DIY Brake Light for Your Bicycle

Hi everyone!

In this quick ible I'm going to show you how to hack a cheap LED light making a useful Brake Light for your bicycle.

It's a really simple and easy project but I took some photos to make this instructable more understandable. Follow the next steps to understand how I made it.

If you want to see it in action you can watch the video in the last step!

P.S. I entered the "Bicycle Contest" so If you like this project please remember to vote for me!

Step 1: Materials & Tools


- cheap bicycle light

- double core electric wire

- 1x mini momentary push button

- heat shrinking tubing

- plastic zip ties


- 1x 10mm bright red LED

- 2x 5mm bright red LED

- small tube


- soldering iron

- screwdriver

- lighter

Step 2: Make It Brighter (optional)

(This is an optional step)

Since the existing LEDs of my 1$ light made a very little light, I decided to change them with brighter LEDs that I saved from another project.

So I simply removed the 3 LEDs, and I soldered 3 brighter ones. (I also changed the chinese batteries with new ones that should be more powerful)

Obviously if you don't need to make it too, you could just skip this step.

Step 3: Solder the Button to the Wire

In order to light up the bicycle light just while breaking, we need to connect a momentary push button to the preexisting switch/button. Since we will fix it onto the lever of the brake, the smaller the better.

So I looked in my switch/button container, I chose one small momentary push button and I soldered it to a double core electric wire.

You can buy 50 of them for less than half dollar, or you can easily get it for free dismounting broken electrical products. Those small push buttons are everywhere.

Then you have to cut the wire at the right length. To measure it, you can follow the red line in the 4th photo.

Step 4: Solder the Wire to the Light

I discovered that the cheap light that I bought was sold without a screw (that should have keep the enclosure closed), so it has a hole on the bottom.

Initially I thought to find a screw of the right size to replace the missing one but then, since the enclosure of the light remains closed by itself, I decided to use that hole to let the wire pass through it.

So I inserted the double core wire, and I soldered the two inner wires to the contacts of the existing ON/OFF button.

(Don't worry about the polarity! Since it is a simple switch added to another switch, you can solder one wire of the double core cable to the left contact of the switch and the other one to the right contact or vice versa)

Step 5: Test It

In less than 10 minutes we made it brighter and we also added a momentary push button.

In the pictures above you can see that the small push button add a function to the light without removing its basic use.

picture#2: If you push just the momentary push button, you can use the "braking light" mode.

picture#3: Instead, if you want it to work as a common bicycle light, you just have to push the ON/OFF button without caring about the added momentary push button.

Step 6: Secure the Wire to the Brake Lever

In order to secure the wire to the brake lever, I used some plastic zip ties.

To make the result a little bit cooler, I decided to use the technique that I learned from this instructable, adding a small piece of 5mm of plastic tubing to each zip tie. You can easily find it inside of an empty deodorant or inside an empty spray bottle.

(For the moment, I used a rubber band to keep the push button in the right place)

Step 7: Secure the Wire on the Bicycle

For the rest of the wire instead, I decided to use other zip ties to secure it directly on the brake wire.

(obviously, if you used like me a wire with a grey coating and you don't like to have that color on your bicycle, you can spray paint it black like the other bike's cables, or you could use directly a wire of the right color)

Step 8: Secure the Button and the Light

To secure the light to the seatpost I decided to use a couple of zipties, adding a small piece of bicycle's tire (inner tube) to make it sturdier and to avoid that the plastic of the light will slip on the metal (of the seatpost tube).

For the button instead, I used the insulating tape. I also added a small piece of sponge over the button to avoid that the tape would have kept it pressed.

Step 9: Finish!! Ride Your Bicycle More Safely

As you have seen, this is a really quick and easy project that everyone can make without problems in less than an hour. It is also a very cheap hack that I suggest to make on your bicycle light in order to ride more safely also during the day.

If you want to see it in action you can watch the video above!

I remember you that I entered the "Bicycle Contest" so If you like this project please consider to vote for me! I really appreciate your support.

Thank you for reading my Instructable. ;)
Feel free to comment and ask if you need to know something!


Bicycle Contest 2016

First Prize in the
Bicycle Contest 2016