Bicycle Helmet Mirror for $2




About: I miss the days when magazines like Popular Mechanics had all sorts of DIY projects for making and repairing just about everything. I am enjoying posting things I have learned and done since I got my first ...

A mirror helps a cyclist avoid automobiles and ride more safely. You can make a mirror for your helmet. You will need a mechanic's inspection mirror ($2 at Harbor Freight Tools), some heavy wire (a coat hanger will work very well), an aluminum soft drink can, some screws, and some aluminum bar stock (not shown).

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Step 1: Cut and Bend the Wire

The wire will be attached to the helmet's visor when finished. Cut 6 inches of wire. Bend it in the pattern you see. Bend at 2.5 inches from one end and 1.25 inches from the other end.

Step 2: Make Tabs for Attaching the Mirror Frame

Cut two pieces of aluminum from a soft drink can. Make them 0.75 inch by 1.5 inch. Fold them over the wire and crease around the wire. Fold them so the printed side is on the inside of the fold.

Step 3: Drill Mounting Holes

Drill holes in the aluminum tabs and in the visor.

Step 4: Attach the Frame to the Visor

Use small screws to mount the tabs and wire frame to the visor. Use a flat washer and a toothed washer behind the nut. The flat washer adds rigidity to the aluminum tabs. The toothed washer keeps the nuts tight. Use a scissors to trim sharp corners from the aluminum tabs. The screws may also be shortened with a grinder or any other suitable tool. The "L" shaped bend in this part of the wire frame keeps the mirror from rotating up or down. This general design also eliminates any need to weld or braze anything.

Step 5: The Mirror to Frame Connection

Cut two squares from a piece of 1/8 by 3/4 inch aluminum bar stock. Dress corners and edges with a file.

Step 6: Make a Groove for the Wire Frame

This part is a little tricky. Make a groove in each aluminum square. The aluminum squares will grasp the wire frame with these grooves. Cutting them by hand with a file is one way to do the job. Clamping the squares together and drilling between them is another way to do the job. It is faster, but the bit tends to wander and go into one square more than the other. If the bit does wander, some correction can be made afterward with a file. The width and depth of the grooves should be a little less than the diameter of the wire so the squares grasp the wire firmly.

Step 7: What You Are After

Pictured is how the squares should fit onto the wire frame.

Step 8: The Aluminum Squares With Drill Holes

The aluminum squares need two sets of holes. One set forms a socket for the swivel ball on the mirror. (The rest of the mirror as it came from the store is not used.) Drill a hole a bit less in diameter than the swivel ball. Dress and fit it with a countersink bit. Drill another hole for the clamping screw.

Step 9: Finished Assembly and Use

Sandwich the aluminum squares around the wire frame and the mirror's swivel ball. Clamp with the screw. Use a toothed washer to keep the nut from working loose. Tighten the screw and nut enough that the mirror stays where you want it. Leave it also loose enough that you can adjust it while riding your bike. I find the mirror works well for me if I can just see a bit of my ear in it. That gives me a reference point for what I see in the mirror. It is not a problem if you adjust the mirror so that you need to incline your head just slightly to see the traffic lane fully. If necessary, you can tweak the bends in the wire frame to get the mirror roughly where you need it and then do the fine adjustments with the swivel features of the mirror and the aluminum squares.

I have been using one of these for quite a while and really like it.

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    15 Discussions


    4 years ago on Introduction

    never used a helmet on a bicycle until after both feet popped out of the pedal toe clips while pedalling hard downhill in high gear and i went careening thru the traffic light at high speed spreadeagled on the center bar with half my weight over the front wheel and my breastbone smashed down hard onto the center post handlebar area at 40 mph

    1 reply
    Phil Bjdillon6

    Reply 4 years ago on Introduction

    I had a couple of crashes that could have left me in a sad state because I had no helmet at the time. Since I have had a crash that cracked the helmet, but saved my head. Your experience sounds painful.

    andrea biffi

    6 years ago on Introduction

    Very useful, but you shouldn't attach anything dangerous as two bolts near your eyes, not to mention an aluminium plate... think what could happen during a fall... yes, I'm five years late ;-)


    6 years ago on Step 4

    I see why you used two bolts instead of one, the sheet metal wouldn't be strong enough for the vibration or the leverage. Good plan!

    1 reply

    7 years ago on Step 9

    Excellent instructable! I'd change step 8 to glue the screw into the one side and use a wingnut to hold it. Still very nice work!

    3 replies
    Phil Bjack002

    Reply 7 years ago on Introduction

    Thank you. Your suggestion might work. The screw is not exactly perpendicular to either of the aluminum pieces. Accommodation for that would need to be considered.

    Phil B2 stroke

    Reply 7 years ago on Introduction

    I did not, either, until I was almost 40 years old. I even had a couple of crashes that could easily have resulted in permanent brain injuries. A couple of years ago I had another crash that cracked the helmet above my ear in two places, but left me without so much as a headache. A crash resulting in a brain injury could easily leave a cyclist a vegetable for the rest of his life.


    8 years ago on Introduction

    Thanks for the ideas. I am working on a decorative but functional rear view mirror attachment, Steampunk style, but my eyes popped at the ball joint on that mirror! I am one happy camper to see that and must now find myself one of those inspection mirrors. I have been researching using ball joints for some things--they make them for small character armatures in stop motion animation. Am trying to figure out if I have the tools to make my own. If I got a workstation for my Dremel, I would almost have a drill press. Thanks again for the inspiration!

    1 reply
    Phil Btesseliot

    Reply 8 years ago on Introduction

    Thanks. I have not had time to check your profile to see where you are located. If you are in the USA, you probably have a Harbor Freight Tools within a reasonable distance. The mirror shown was made in China, so you may be able to find it elsewhere. I hope all goes well for you.


    8 years ago on Introduction

    Wouldn't it just be easier to cut off an inch or 2 of the telescope and crimp or JB weld it to the bent wire?

    1 reply
    Phil Bdlfynrdr

    Reply 8 years ago on Introduction

    Perhaps it would be easier to do one of those two things, but I wanted something more substantial and dependable. But, that is just my opinion.