Today I’m going to becovering on your ride, how to see things better — and more importantly —how motorcycle light bulbs can help you see and be seen better. But in order todo that, I’m going to have to toss around a few electrical terms. You know,like watts and volts and amperage.
Wait! Don’t hit the Back button,because I’m going to try and make this as easy to comprehend as possible.A watt is a unit of measure that takes into consideration themathematical relationship of volts and amperage. What it looks like is this:Watts = Volts X Amps.
The standard motorcycleheadlight that comes attached to most of today’s models has a rating of 55/60.That means the low beam draws 55 watts (12 V X 4.5 A), while the high beamdraws 60 watts (12 V X 5 A). The higher the wattage, the more light issupplied.
How we doing so far? Still with me?Good. Now a great number of halogen headlamps are using a two-piece system thathas a reflector with a changeable bulb. These changeable bulbs are givennumbers like H3, H4, H7 and H13. There are higher wattage bulbs available inthis type that can provide even more illumination.
For instance, J&P Cycles offersGerman Rally bulbs in 55/60, 80/100 and 100/130 wattages. But I digress. Goingback to our formula, a 100W low-beam bulb draws 8.3 amps (12V X 8.3 A = 100W)while a 130W high-beam bulb draws a whopping 10.8 amps (12V X 10.8 A = 130W).
These bulbs add new meaning to theterm bright! However, this is acceptable up to a point. Higher wattages requireheavier components to handle the higher current load. These higher wattagesincrease the amount of heat produced and require a metallic or glass reflector.Some lower-priced halogen reflectors are made of plastic, and these high-outputbulbs can easily melt the unit. In addition, the wiring on your bike is onlydesigned to handle a specific amount of power.
Changing to one of these Rallybulbs will most likely require an increase in the size of the wire going to thelamp in order to keep it from melting or burning up. Sounds like a lot ofeffort in order to get a brighter lamp.
But this brings us toa neat solution engineered by the PIAA Corporation. What PIAA has done, isincrease the light output, without increasing the wattage required. These bulbsare a bit more expensive, but modifications to your bike are not required. Andthat’s a good tradeoff, if you’re asking my opinion.
Another thing to consider withthese super bright bulbs is the effect they have on the bike’s charging system.All ’66-’84 Shovelheads come with 15-,17- and 22-amp alternators, and ’84-’88 Evo Big Twins have 22-ampalternators.’67-’79s Sportsters have 10-amp charging;’80-’84s have 13 amps;’84=-’90s have 19 amps; and bikes between ’91 and ’05 have 22-amp systems.
Upgrading to thehigher-wattage bulb is impossible on the smaller-amp charging systems. Toupgrade, the 22-amp system would be the lowest amp output recommended. Therejust isn’t enough current output to run everything required, and keep yourmotorcycle battery charged. Big Twins built from ’89 and onward have a healthy32-amp alternator, so this isn’t a challenge.
Now, what’s your opinion of LEDlighting? This acronym stands for Light Emitting Diode, and these little guysprovide a lot of light with minimal wattage requirements. Used as a taillight/brakelight on our bikes, no changes are required. However, when used as a turnsignal, we’ve got issues.
In applications that have aself-canceling turn signal, a load equalizer is required. Since the LED lightchanges the wattage in the circuit, the difference in current draw will confusethe original processor into thinking that the bulb is burned out.
This can cause a no-flash ordouble-flash condition and believe me, we get a ton of calls about this. A loadequalizer, like those from Badlands, will correct this condition by fooling theprocessor into thinking the stock bulb is still in the circuit. Your new LEDturn signal will flash and cancel normally. A load equalizer is also requiredif a small, marker light is used as a four-way flasher.
Due to possible heat buildup in theunit over a longer period of time, it’s a good idea to keep usage down to aminimum. And just a reminder: While these small, marker lights look good on ashow bike, they should not be used on the street, because they can’t be seen aseasily as a DOT-approved light, especially in the daytime.
I certainly hope this sheds somelight on today’s subject, and hope I set things out in an understandablemanner. If not, the friendly and savvy tech staff at J&P Cycles is alwaysavailable to answer any questions that you may have.
