Bicycle Light Sources
The cheapest bicycle headlights use a tungsten filament lamp. A more expensive, but brighter and more battery efficient alternative is the halogen lamp. The brightest type is the high-power high intensity discharge (HID) light, which requires special circuitry and a powerful battery. Some self-contained light-emitting diode (LED) headlights have largely supplanted filament based lamps with lower expense, higher light output, and better battery life. High End LED based systems are also poised to make even the HID based systems obsolete.
Lighting decisions may be driven by the power source (e.g. tourists may prefer a dynamo system) and by the amount of light required (e.g. off-road riders may prefer a HID rechargeable), but often it is a matter of personal preference or local availability. A low power headlight and a rear red LED often suffice for cycling at low speeds in familiar areas with sufficient ambient lighting. In more challenging conditions, upgrading to a more powerful headlight is recommended. The drawbacks of more powerful lighting may include some combination of greater weight, greater expense, and shorter run time.
A common setup for a bicycle commuter might include:
- a quartz-halogen or high power LED headlight powered by a rechargeable battery pack or dynamo
- a LED tail light, either steady or flashing/pulsating
- a flashing/pulsating LED front light for conspicuousness and as backup