A white beam cuts glisteningly through the darkness. Electromagnetic waves dance between the trees, sparkling and flashing in autumnal drops of water. The HID torch on the head turns night into day. Metal salts mix with xenon gas, receive an electric shock and vaporise into plasma. This is so bright that the lamp would also cut a fine figure as stadium lighting. In the forest, it makes the trail so bright that even fast downhills are no problem. In autumn, when the days get shorter, these high-performance lights are perfect for biking. Mounted on the helmet, they always illuminate the trail in your line of vision. With a small lithium-ion battery, they burn for up to four hours, which is enough for a longer tour. However, these high-end lights are also really expensive. Prices range from 440 euros for a simple lamp with an internal battery to 760 euros for a high-end "Supernova". It's cheaper to go biking with an LED lamp. Good LED spotlights for the trail are available for as little as 140 euros. To date, however, only one LED lamp exceeds the 900 lumen light output of standard HID lamps. The Lupine "Betty" produces 1400 lumens with seven LEDs. However, the price advantage of conventional LED lamps is lost in this high-tech league.
HOW LED & HID LAMPS WORK
What is behind the abbreviations "LED" and "HID" and how do the two different lamp concepts work in practice? BIKE brings light into the darkness of lamp technology.
HID (HIGH DENSITY CHARGE)
Gas discharge lamp with ballast to prevent burn-out (ballast, right side of picture). Two electrodes surrounded by a xenon-metal salt mixture replace the filament. A starting current (6000 V) ignites the mixture. Bright plasma is created.
LIGHT DISTRIBUTION HID
The light distribution depends heavily on the reflector used. Ideal when the trail is well illuminated both in the distance and directly in front of the bike. The much stronger luminosity of the HID lamp is clearly recognisable.
LED (LIGHT EMITTING DIODE)
Semiconductor compound that converts electricity directly into light. White light is obtained from blue LEDs (highest efficiency) and an overlying yellow fluorescent layer (image on the right). Power LEDs must be cooled (aluminium carrier/housing).
LIGHT DISTRIBUTION LED
The cone of light from the LED lamp starts well in front of the bike, although the target marking is the same. The peripheral illumination is not perfect either. Current HID models are only surpassed by the Lupine "Betty" LED lamp.
EXAMPLES BIKE LAMPS:
