How to Make Self-Illuminated Reflectors for a Bicycle

Riding bikes at night can be a dangerous adventure. While motorcycles have loud engines and a bright headlight to alert motorists to their presence, bicycles traditionally lack both of these safety features. The only mandatory safety feature on a bike are reflectors. Unfortunately, reflectors only work when a car is already in close range to the bike, and the reflected light is easy to miss, as it is fairly dim.

If you find yourself in need of riding your bike at night and you’re worried your safety on the road, this project is for you. This tutorial will show you how to add internal lights to the stock reflectors on your bike. These reflectors will be illuminated without any direct light source, and will shine far brighter than an average bike reflector.

Items Needed:

(2) white LED light bulbs
(2) 150k – 350k resistor (depends on bulbs used)
(2) small metal boxes (round Altoids tins are perfect)
(2) small switches
(2) 9v battery connectors
(2) 9v batteries
Hot glue gun + glue sticks
Soldering iron and solder
Drill or dremel
1/4″ drill bit
A few cotton balls

Step 1: We’re going to insert an LED into the back of the reflectors. The LED will be powered by a 9v battery with a toggle switch for turning the light on an off. The entire set up will be stored in an Altoids tin to prevent water damage and keep the unit neat.

Step 2: Using a 1/4″ drill bit, drill a hole in the back center of the reflector. Only drill through the back – don’t go through the front. Drill slowly to prevent cracking.

Step 3: Strip the ends of the 9v battery connector wires. Using the soldering gun and the solder, connect the black wire (negative) to the short wire on the LED bulb. The short wire is the negative.

Now, solder the red battery connector wire to one of the connectors on the switch. On the connector across the it, solder the resistor. Now, solder the other end of the resistor to the long end of the LED bulb.

Attach the 9v battery to the connector and flip the switch to make sure it works.

Step 4: The entire battery unit is going to be stored in the tin, and the tin will be glued to the back of the reflector.

Using the drill, drill a hole in the bottom of the tin, in the center. Also, drill a hole on the side of the unit.

Put the battery and light inside the tin. Push the LED light out of the hole on the bottom. Place the tin flat against the reflector with the LED light going into the hole in the back of the reflector. Use hot glue to glue the tin in place.

Once the tin is secured, insert the switch into the hole on the side of the tin. Use a glop of hot glue on the inside to hold it in place.

Finally, fill the tin with cotton balls to keep the battery from knocking around. Place the lid of the tin on firmly.

Step 5: Repeat with any other reflectors you would like to illuminate.