Cheap Lights by Pete Knox
Night riding can be fun if you have good lights. The days of the French Wonder Light leg lights are gone. Real lights are now readily available, but they cost a lot if you want power and hours of it.
With a little bit of hand work and a trip to Home Depot and Radio Shack, you can easily build a killer light for a fraction of the cost of a commercial light. You could also pay a visit to an emergency lighting store and buy a six volt emergency light for $20 and an emergency light battery for $20 and be ready to go with far less effort than making a light yourself, but you'll miss half the fun of being creative. Look up in the bathroom in a commercial building or look up in most stairwells and you will see a six volt emergency lighting system bolted to a unitary battery box with charger. Just separate out the components and bolt the light and battery onto your bike. Weston Emergency Lighting, 894-1585 sells halogen 6 or 12 volt sealed beam light units (light heads with lens, case, and snap ring to hold the bulb) for about $20.
The following will enable the truly frugal to build a seriously bright and powerful 20 watt halogen sealed beam spotlight that will light up the road for a couple of blocks (my car's headlights are 45 watts), cause most Chevy Suburban drivers to slow down and hug the other side of a country road when they see you coming (with 20 watts they are guaranteed to see you coming a long way off!), and run for three plus hours and do it for less than $45.
Light: 12 Volt, 20 Watt "Spotlight ESX" Halogen spot light with reflector and lens, GE Order Code 19458. Available at Home Depot for under $10. 20 watts on a bicycle is extremely bright and powerful. Mr. Lightbulb in Newton (888) 828-2852 also sells these 20 watt lights. Smaller wattage bulbs are available but they lack the reflector and lens of the GE bulb.
Battery: Powersonic Gel Cell PS-1270 Battery. 12 volts, 7 amp hours, 6 lbs., 6" x 2 1/2" x 4", life span 500 cycles at 50% discharge. Atlantic Battery in Watertown, 924-2868, 80 Elm St., behind Bradlees at Arsenal Mall sells their house brand version for $23.00. Also available from Keystone Batteries in Winchester, 729-8333.
Amperage: Watts / volts = amps. Light run time = ( Battery Amp-hour Rating / (Watts / volts) ) x .8. Therefore, a 10 watt 12 volt light needs .833 amps to run it for one hour. However, discharge rates are not linear, and you do not want to discharge fully, so you need a few extra amp hours to predict run time or you need to throw in a fudge factor when predicting run time. For a 7 AH battery with a 20 watt bulb: ( 7 AH / ( 20 Watts / 12 Volts ) * .8 = 3.4 hours of run time. If a shorter run time is all you need, you can save money and weight by buying a smaller battery.
Charger: Needs to produce 13.6 to 14.7 volts to charge a 12 volt Gel Cell, or else it will never fully charge. Voltage will rise to 16 volts when battery is fully charged. A PS-1270 battery should be chargeable by a 1.5 AH motorcycle battery charger. A 750 MA Powersonic PSC 12-800A, 13.6-14.7 volt charger costs about $45 at Keystone. You cannot use a high powered car charger on a sealed battery. Cheap 750 MA 12 volt chargers are probably available at most electronic hobbyist stores. Sears automotive departments also sell low amperage chargers used for permanent charging stations.
Housing: Made out of some PVC plastic plumbing pipe and a few small circles of Lucite Tuf clear plastic (both are easy to cut, drill, and sand as needed). Take the PVC plastic plumbing pipe, 2" in diameter, (Type I SCH 40 ASTM D-2665), and saw off a 3" piece. From the source pipe, cut off three 1/2" wide rings and then cut a 3/4" gap out of each ring. Compress one 1/2" wide ring and insert it into the front of the light tube deep enough to leave room for a Lucite lens to sit across the front of the light tube. Cut two circles from some Lucite Tuf to fit inside the light tube. Epoxy cement across the front of the tube one Lucite circle for an outer lens to protect the Halogen light from water. Insert into the PVC pipe the GE Halogen bulb/reflector (it fits flush) with some 24 gauge lamp cord soldered to the two end prongs on the light bulb. To hold the bulb securely in place and stop it from jiggling on the road, run a bead of clear silicone caulk around the joint between the bulb/reflector and the PVC pipe. Insert the second 1/2" ring into the back of the light tube and slide it up against the back of the bulb/reflector and bead it with some Epoxy cement. Insert the third 1/2" ring into the back of the light tube and bead it with some Epoxy cement, then pass the lamp cord through a hole in the second circle of Lucite and then Epoxy the Lucite onto the back of your light tube. Solder a Radio Shack Inline Coaxial DC power jack (Female), 5.5 mm OD, 2.1 mm ID, Cat. No.: 274-1577B onto the end of the line cord, solder a mating Radio Shack inline Coaxial DC power plugs (Male), 5.5 mm OD, 2.1 mm ID, Cat. No.: 274-1569A, onto a second piece of line cord, then solder the other end of the second piece of line cord onto the battery terminals. The inline power plugs will act as a power switch and will let you store the battery separately from the light. If you don't want to go to the trouble of inline connectors, then put in a simple inline on/off switch.
Mounting the light: Take a few inches of some metal plumbing strap hanger (soft and easy to work with) or hose clamps which you may bolt or screw to the PVC pipe and either attach the light to your handle bars using a hose clamp or rubber band it to the top of your helmet (many helmet liners will just pop out if you tug on the Styrofoam insert, which will allow the rubber bands to go into the helmet but not touch your head). The helmet mount looks a little weird, but having the light on top of your head greatly increases your visibility, your ability to see pot holes and road hazards, and your ability to shine it directly at motorists approaching from side roads, rotaries, etc., thereby ensuring that you have been seen. The extra weight on the helmet is annoying the first few times you ride with it, but your neck will grow extra muscles right away.
Mounting the battery: I made a wooden case for the battery, tapped in a couple of 'U' nails to the bottom outside edges of the wooden case, and then tied the case to the rear rack with some nylon cord and then bungeed the case/battery to the rear rack. The bungee is needed in addition to the nylon cord to take up the inevitable slack in the cord. If you lack a rear rack, you should be able to make a water-bottle-cage-style battery holder by drilling two holes into some sheet aluminum so as to mount onto your down tube's water bottle mounting holes and then strap the battery to the sheet aluminum.
See you on the road. Be safe, be seen.