Posted April 14, 2012 by Adam in mountain bike accessories

DIY Bike Light – Your step by step guide

Bike Light Assembly – Part 2 of our DIY Halogen Bike Light Guide

Part 1 of this DIY bike light guide looked at the parts and tools needed to make your own Halogen bike light.

backClick back to find out what parts and tools you need

Now that you have all your parts and tools, let’s put it all together…

Paint Your Light

    1. Roughen the backs of the globes and clamps with the sandpaper so the paint sticks. If you don’t it will flake off and look crap.
  • Spray the backs of the globes, clamps and ceramic clips with heatproof paint and let dry. Painting looks better and also stops unwanted light getting in your eyes.


Mount Your Light

    1. Wrap a small rubber strip around the ‘squared’ section of the globe. Use to tape to temporarily hold it if necessary.
  • Fit one of the small hose clamps over the rubber and globe.


  • ‘Square off’ the clamp so it fits better. Try to get the clamp to more closely match the globe’s shape.


  • Loop a large clamp though the small clamp (between the clamp and rubber strip).


  • Tighten the small clamp, holding it all together.


  • Wrap a larger strip of rubber around the bar and mount the light using the large clamp. Tighten enough so you can still adjust each globe’s angle by hand.


  • Repeat for the other globe.


  • Wrap another strip of rubber around the handle bar and fit the switches with tape or zip ties. Mount one on each side so you can operate them with your thumb.


Wire Up Your Bike Light

Note: Before you start cutting wires, remember to make sure you leave some slackness for later adjustments and so the handlebars can fully turn!

    1. Fit the ceramic clips onto the globe pins.
  • Measure from the globe to the switch mount and cut 1 wire on each clip to suit. Then fit a female spade connector.


  • Cut lengths of single wire to run between each switch and the other “2 into 1 connector”. These wires should be long enough to mount both “2 into 1 connectors” together.


  • Fit female spade connectors to the wires’ switch ends.


  • The longest wires will be between your rechargeable bike light the battery and the “2 into 1 connectors”. Fit the fuse link into the battery end of the positive line, using male and female spade connectors, and a female spade connector to the battery end of each wire.


  • The positive lead should connect into the “2 into 1 connector” that runs to the switches, while the negative lead should join the connector running to the globes (see wiring diagram below).



Bike Light Wiring Diagram
Click to see the Wiring Diagram (opens in new window)


    1. Connect the wires as per the wiring diagram, double checking all connections!
  • Zip tie or tape loose wire to the bike, and charge and fit your battery.


  • Adjust the globes so one points a little higher for high beam – extra distance is very welcome at high speed at this will give you a nice bright bike light! When you are happy with the angles, tighten all clamps snugly.


Note: Ensure clamps around the globes are tight enough to retain the globes! Be careful… I have seen a globe break, partly because the clamp was too tight – it also had no rubber lining, and an inflexible, wide clamp, not shaped to match the globe. If you follow this guide and use a bit of common sense you should be right.

Clamp globes, not ceramic clips – globes will fall out if you rely on the push fit of the ceramic clip.

Now wait until it is dark… and enjoy the freedom and feel of night riding.

Like to Tinker?

The above guide hopefully shows you how to set-up a basic – but functioning halogen diy bike light system, however if you like to tinker, then don’t stop here. It is possible to buy digital controllers to run your lights at different wattages, or you can make lights with housings, helmet lights, tail lights and all sorts of electrical craziness.

For some more detailed info have a look at