How Use a Flashlight for a Bicycle Headlight



Introduction: How Use a Flashlight for a Bicycle Headlight

About: I was electrical engineer for 22+ years, then went back to school for 6 years and became a dentist.

Need to ride at night once in a while? Don't want to spend big bucks for a bike specific headlight? This instructable is for you!

Step 1: Here's What You Need

A bike helmet. Riding without one is silly, riding in the dark without one doubly so! I like having a light on my helmet because it points where I am looking and can be pointed at drivers on cross streets at intersections. Get a helmet that fits you properly and make sure the straps are adjusted to keep it in place if you go down. A helmet that doesn't stay put when you crash is as bad a no helmet at all!

I like my Giro for the good buckle/strap system and the ventilation. You can get good helmets cheaply by buying last year's model closeouts at places like Nashbar, Pricepoint, etc.

Just about any helmet will work- almost all have plenty of vent holes- you'll see why that is important in a minute...

The other things you need are a flashlight- this thing is going to be on your head, so a small one is best. I used a "River Rock" flashlight that I bought at target for $20. It uses two AA batteries, it's weather proof and VERY bright. A pair of alkaline batteries will give full output for 4-5 hours. Rechargeable NiMH will provide full output for 2-3 hours. That's plenty for most bike commutes in the dark.

Oh yeah, you'll need a couple rubber bands too. I used whatever I had around. Just make sure they'll fit...

Step 2: Putting It All Together.

Put one end of the first rubber band around the flashlight. Put the other end down through one of the vent holes in the helmet. Bring that end back up through another vent hole and loop it around the end of the flashlight.

Step 3: Almost Done!

Now do the same with the other rubber band at the other end of the flashlight. Make fine adjustments to the position of the flashlight by adjusting the rubber bands so that the light points forward and is approximately centered.

Done! That wasn't hard, was it?

No go out and ride, but watch out for cars!

Step 4: Improvements/Variations

Use velcro straps to hold the flashlight instead of rubber bands if you're going to be riding in the dark a lot. Velcro straps won't break after repeated exposure to your sweaty head.

Use sticky velcro tape and put one piece on the helmet and its mate on the flashlight. Then you can just stick it on and go.

Or you could just keep a few extra rubber bands around...

You can do the same thing to hold the light on the handlebar stem of your bike if you don't want it on your head. It is probably better for racing-type bikes because of the crappy position in which you have to hold your head to see where you are going.

I ride a recumbent so the top of the helmet is fine for me.

Be the First to Share


    • Sculpt & Carve Challenge

      Sculpt & Carve Challenge
    • Fabric Challenge

      Fabric Challenge
    • Eggs Challenge

      Eggs Challenge



    12 years ago on Step 4

    Neat. I did something similar with two small lights & epoxy. One light on each side, and they merged into a much wider beam and extra bright in the center. Regular epoxy didn't work so well, but the silicon is still on after three years & a lot of rain.


    12 years ago on Introduction

    I use a similar arrangement on the front of my helmet. I've always been a little concerned about the possible effect on the protective value of the helmet if you took an impact over the torch.

    Mark Rehorst
    Mark Rehorst

    Reply 14 years ago on Introduction

    I don't recall exactly what was on the package, but I think it is a Luxeon K2. It has a DC-DC converter to keep it at constant brightness as batteries discharge. It is plenty bright for riding home on streets in the dark but I wouldn't try barreling down singletrack with it in the dark.