by Victor Wanchena There is a line from a Robert Frost poem that reads, “... the woods are lovely, dark, and deep. But I have promises to keep, and miles to go before I sleep.” Night riding poses a variety of hazards to a rider and the only tool on a motorcycle to combat the night is your headlight. Riding faster than you can reasonably see at night is a common habit with riders and a major safety concern. Improving your motorcycle’s lighting has real benefits. If you can see it, the less likely you are to hit it. Being able to relax because you can see where you’re going reduces rider fatigue.
Your headlight has three main components. The most obvious is the bulb, made of a tungsten wire filament that is encased in glass, surrounded by an inert gas, usually halogen. When an electrical current is passed through the filament it does two things; it gives off light and heat. In simple terms, it does this because there is resistance to the flow of electricity in the filament. If you want the Mr. Science explanation, check out the list of resources at the end of the article. The light output for a bulb is measured in watts, generally the greater the watts, the greater the light. The second component of your motorcycle headlight is the reflector. The reflector is simply a mirror that directs the light forward, as well as giving shape to the beam. The last piece of the puzzle is the lens. The lens protects the bulb and the reflector along with helping shape the beam of light. Most lenses have bumps and ridges on the interior to diffuse the light into the pattern the engineers desire. The size and shape of the lens and reflector make a great deal of difference in how the light is spread. The general rule is the larger the reflector, the better it is able to throw the light down range. A large lamp will give you the best long-range lighting, while a small convex lens will give a wider spread of light, close-in. The newest innovation in headlights is High-Intensity Discharge lamps. Commonly called HIDs, these are not standard-filament bulbs. More closely related to streetlamps, HIDs produce light by jumping a high-voltage arc through a gas. This arc ionizes the gas, producing light. Although more complex in their inner-workings, HIDs produce more light, with less energy. The light is a whiter light than any incandescent bulb and very close to daylight. Light color is measured in temperature, by degrees Kelvin. For reference, a standard halogen bulb produces light around 2,800 degrees Kelvin, while a HID bulb produces light in the 4,100 degrees Kelvin. For an in-depth explanation of color temperature see the resource list. The light from a HID bulb has a couple real world benefits. Since it is very close to daylight in color, it reduces eyestrain while driving and it illuminates things, like a well-camouflaged deer standing roadside, better than incandescent light. Their drawbacks are the system complexity. Each lamp needs a ballast to change the voltage from the motorcycle’s 12 volts to the 25,000 volts needed to create the arc. While HID bulbs last much longer than quartz halogens, they are much more expensive. Now to dispel some myths, the biggest one is in regards to light color. Blue-tinted bulbs meant to replicate HIDs aren’t of real benefit. They physically emit less light compared to standard quartz halogen bulbs. The coating on the bulb reduces the light output in the red, orange and yellow frequencies of visible light. Reducing light from your bike to the road is bad. While the color of the light might be better than a standard halogen bulb, the diminished output is major drawback.
Auxiliary lights have the advantage of allowing you to tailor the light to your needs. Common types are driving beam, long-range spot, or fog lights. If you choose extra lights, shop for ones that fit your needs and your bike, not simply for style or price. The downside of extra lights is that you need to find room to mount them and extra power to run them. Mounting is always a prime concern. The easiest is to use a model-specific bracket or light bar. There are many companies offering what you need. A search of the Internet is a good place to find model-specific mounts. Retailers like www.cyclegadgets.com offer a wide range of products. Home-brewed mounts are easily fabricated by anyone handy and cost next to nothing. Power draw must also be factored in. Consult your owner manual as to the wattage of your charging system. Most modern bikes have enough output to run a pair of 55 watt driving lamps, but if you have any questions about it, consult your mechanic. Beam pattern is a matter of personal preference and there are trade-offs. A long-range light will give poor side-illumination, while a wider beam may not reach as far as you need it to. With any light, you should also consider how it affects oncoming drivers. Installation of the Hella kit was very straightforward. Using mounting brackets made specifically for our test mule eliminated most of the complicated fabrication. The wiring of the lights was dirt simple as the Hella kit includes a pre-made wiring harness. The toughest chore was finding a place to hide the ballast. On unfaired bikes this would be a real chore, but on our drone it was just matter of securing them behind the body panels.
The lights were measured on a test range, read golf course, with a light meter at a single aiming point. As was expected, older bikes with poorly shaped lights (a.k.a. less efficient bulbs, reflectors and lenses) did dismally, with most throwing 8 foot-candles. Modern bikes performed much better, but there was a great variation from bike to bike. Measurements ranged between 20-40 foot-candles. Standard, incandescent driving lights added to the output generating readings of 50-70 foot-candles. Most in this category were running a pair of 55 watt driving lights. The big dogs were throwing over 200 foot-candles, but this came at a cost. To get numbers that high you need to run 200-300 watts of extra lights. The king was an Iron Butt Rally hooligan with a retina burning, triple HID setup at 750 foot-candles. Yikes! The Hella Micro DE HIDs put a very respectable 125 foot-candles using much less power than many competitors. The majority of the high output lights in the test were Hella, KC Daylighter, or PIAA with a few bargain bin specials in the mix, but these performed poorly and don’t rate any mention. It should be noted that because meter readings were taken at only one point, our test did not take into account over-all beam shape. The highest readings were achieved by focusing all light on one point with little illumination outside that area. Resources: Light Bulbs Color Temperature Aftermarket Light Manufactures M.M.M.
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This article originally appeared in the September
2005 issue of Minnesota
Motorcycle Monthly.
Headlight technology has come a long way from the early days of candles and oil lamps. Many early motorcycles used a carbide lamp. They burned acetylene gas, but were, by all accounts, useless above walking speed. Thankfully, the electric incandescent lamp was invented. The incandescent lamp is rather simple in its design. Flow enough electricity through a wire filament and it glows. The last 20-years have seen great strides in motorcycling lighting. Many modern headlights are a work of art and science.
If you want to upgrade your lights you have two choices; install a higher-wattage bulb or add auxiliary lights. The legal limits for standard headlights is 55 watts low beam and 60 watts high beam. There are plenty of over-wattage bulbs on the market. They come in a variety of power ratings. These have the advantage of being inexpensive and basically plug-and-play with one big drawback. With increased power output comes increased heat. This excess heat can damage the reflectors by melting them, as many are now made out of plastic. Not good. The increased draw can actually melt wiring. I learned this one the hard way. If you were to consider an over-wattage bulb, you would be well advised to upgrade your wiring to a higher gauge. Also, these bulbs are technically illegal for road use. If you decide to try an over-wattage bulb, go with a standard low beam wattage of 55 watts, and a boosted high beam of 75-90 watts.
MMM was able to test the Hella Micro DE HIDs against a wide variety of lights at our secret lighting shoot-out. While we didn’t have any big surprises, the results were very interesting. 