How to Mount a LED Headlamp (Miner's Lamp) Light and Rear Blinker on a Bicycle Helmet

 Bicycle lights can be overpriced, theft-prone, and illuminate too narrow an area. LED headlamps are inexpensive and look where you do. Here's how to mount one on a helmet.

Part1

Gather parts

1. 
   1
   Choose a bike helmet to modify. If you're into bicycling, you should already have one. If you have more than one, use the old one, at least first, in case you ruin it. A helmet with a flattish rear end, not a pointed one, will be easiest to use.
2. 
   2
   Pick out a headlamp for adaptation to the helmet. (A lamp that straps onto the user's head, associated with mining.) It must have a hinged front light mount to direct the beam up and down, with a wide adjustment range.

   • Preferably the front light will pivot within a low-profile enclosure rather than swinging on an arm, and the kit will have a rear-mounted battery pack with a bright red rear flasher, a high-power white front light, a stretchy coiled wire connecting the parts, and take relatively high capacity AA batteries. LEDs are a virtual necessity for a long, bright life. An old one with a dirty or bad strap would be perfect, since you won't use that part anyway.
3. 
   3
   Select a suitable adhesive to stick them together. Heavy-duty automotive trim style double-sided tape or epoxy putty are convenient and fill gaps; liquid epoxy is stronger. Get a thick, fast curing variety to not run off of curved surfaces.

   • Other adhesives may work, but finding one that will bond to but not attack helmet materials such as a mix of plastic and foam can be tricky. Clean all mating surfaces and allow them to dry for a good bond.

Part2

Assemble

1. 
   1
   Remove the headlamp strap. Take the light and any other electrical parts, such as a rear light, battery holder, and associated wires, off of the strap. The strap will not be needed for this project.
2. 
   2
   Test-position the components. The main light must be mounted where it does not tilt to one side or the other - many have a narrow beam, so accuracy is critical, must have have an unobstructed path forward, must be able to pivot to shine straight ahead (preferably with some extra downward adjustment available) rather than tilted uselessly up, and must not be at the lower edge of the helmet but instead higher up where it will not knock into your face in an accident.

   • Placement of the battery pack is flexible if it does not have a rear light, but the rear light, whether or not integrated into the battery holder, must shine straight back. The battery door must be openable when the holder is fixed in position. When test-positioning components and checking illumination angles, tilt the helmet to face straight forward as it would be in use, rather than tilting down as it would sit on a table.
   • If the headlamp has separate front and rear components connected by a cable, the position of the front light forward to back along the crown may be chosen to take up excess slack in the cable. (The cable should not be kept in tension to avoid stress to it, to avoid stress to the components, to avoid stress to flexible adhesive such as tape that it may pull loose and crooked, and because tolerances help ensure successful construction.)
3. 
   3
   Mount the front light. Noting the constraint of placement of the rear battery pack or light, if any, affix the front light to the helmet as you had determined to be appropriate. It must face straight ahead, so check its path in a dimly lit room and tweak its direction as the adhesive hardens (or before you firmly stick down double-sided tape). Allow adhesive to cure fully before proceeding so it stays aligned.
4. 
   4
   Mount the rear light. If the helmet does not have a suitable mounting surface, a gentle curve can be built up with double sided tape, epoxy putty, or epoxy.

   • If it has aerodynamic-looking tail ends of spikes at the back protruding well beyond its overall thickness, you might carefully trim these in a relatively sheltered area (not the rear extremity of the overall helmet) to create a small flat mounting area while not harming the overall structure.
   • Epoxy is very strong and headlamp components are very light: a large mounting area is not needed.

Part3

Ride

1. 
   1
   Turn on the front and rear lights. Choose power and blink settings. Blinking lights front and back are great for being seen even when you have enough light to see.
2. 
   2
   Put on the helmet.
3. 
   3
   Adjust the front light up or down to suit your preference. Enjoy your ride!