Introduction: Five Dollar Bike Light

Picture of Five Dollar Bike Light

If you have ever looked at bike lights you already know, they are expensive! I found myself in need of a light, and unwilling to pay a high price. So I did what I often do, I stopped at the hardware store and got to work!

As with all of my projects, I made it at TechShop! (

Step 1: Gather Materials

Picture of Gather Materials

For the $5 Bike light you need:

2 3-1/2 inch LED Flashlights
2 3/4 inch PVC Slip T-Fittings
2 #2 Pipe Hangers
1 piece of 3/4 PVC (about an inch)
1 1/2 inch long 1/4-20 bolt and nut.




Paint (I used Truck Bed Coating)

Step 2: Cut the T-Fittings

Picture of Cut the T-Fittings

The T-Fitting internal diameter is smaller than the body of the flashlight. We are going to use this to our advantage, to provide clamping force to keep it stable.

Slit the T- fittings as shown. I prefer to do this on the bottom, where it will not be seen.

Step 3: Connect the T-Fittings

Picture of Connect the T-Fittings

Using your small piece of pipe, attache the T-Fittings as shown.

I didn't use glue. The pipe and fitting fit together tight enough to hold together. You could alternatively use screw or long pop rivets to secure the fittings.

Step 4: Connect the Hangers

Picture of Connect the Hangers


On my version, I cut the conduit hanger to remove the end bolt. I did this simply because I thought it looked better.

Using the 1/4-20 bolt and nut, attach the two hangers as shown.

Step 5: Test Fit and Adjustment

Picture of Test Fit and Adjustment

Gently pry the slit in the PVC T-Fitting, place something in the slot to hold it open.

Slide the flashlights into the fittings. You should have a snug fit. If you don't wrap some tape around the barrel of the flashlights and reinstall them.


This was easily the most difficult part of the project. The PVC is very stiff. I finally resorted to boiling water and soaking the fitting in it to soften it up. Once I got the flashlight in, I let it cool. The PVC retained the shape and could be pried apart easily for installation of the flashlights.

Open the second hanger and install it on the bike. Tighten the bolt.

At night, turn on the flashlights and adjust them to illuminate the path in front of you. Draw a line on the PVC and the hanger to aid in alignment later.

Remove the lights from the bike.

Step 6: Paint

Picture of Paint

If looks are very important, now is when you want to smooth the piece and remove all visible lettering and such.

Sand the mount to help the paint stick. Sand the hangers. Be careful not to sand off your alignment marks.

Clean everything well, and reassemble.

Prime and paint. I used a plastic primer, a metal primer, and 'Truck Bed Coating'.

Let the mount dry for a couple of days. This will let the coating dry and harden.

Step 7: Assemble and Install

Picture of Assemble and Install

Gently pry the slit in the PVC T-Fitting, while pushing the flashlight in.

Slide the flashlights into the fittings. You should have a snug fit. If you don't wrap some tape around the barrel of the flashlights and reinstall them.

Open the second hanger and install it on the bike. Tighten the bolt.

Step 8: Done!

Picture of Done!

Here it is, a finished bike light!

The switches on the back are still available, as are the screw off battery cases.


Eric Brouwer (author)2015-02-10


jamesk891 (author)2014-10-09

Cars come with two headlights so why can't bike lights be sold as a double.This is a simple and cheap solution to the question.As a comparison , I looked on ebay and they cost around $25-$30 + postage depending on where you live.These materials , I already had and then bought two torches that have a flashing red beacon on the end for $2 each.The result , twin headlights + twin warning lights all in one housing that can be reveresed and used either on front or back of bike.

awinter155 made it! (author)2014-09-13

Thanks so much for posting this! Your project is very clever and the instructions are great as well. I enjoyed making this and use it a lot. Thanks again!

glowgerm (author)2014-05-25

This was a great project. I really light up the streets with this set up!

craftclarity (author)2014-05-23

These are really nice.

I probably would have put red lights on the back, but that's just me. The way everything mates up, it looks like it was designed that way, which is really cool. Nice work!

Dustin Rogers (author)2014-05-01

nice solution!! I love PVC and LED projects.

Bri_Aday (author)Dustin Rogers2014-05-03

Me too! So much PVC, so little time. :)

M3G (author)2014-05-01

Nice work!

Bri_Aday (author)M3G2014-05-03


rimar2000 (author)2014-05-01

Very clever design!

Bri_Aday (author)rimar20002014-05-03


About This Instructable




More by Bri_Aday:Una lámpara para bici por $5Uniones de PVC elásticasFive Dollar Bike Light
Add instructable to: