Night riding and LIGHT CHOICE

Discussion in 'Cycling Equipment' started by starship, Jul 1, 2004.

  1. vonnieglen

    vonnieglen New Member

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    We usually use a two bulb system on the handlebars and a helmet light. We also have numerous flashing LEDs, reflective clothing and a back-up LED headlight for when we discharge our main batteries completely. On the flats, I just use one of the two bulbs on the bars and the helmet light. If we are going on a long ride I try to ration a bit depending on how far we are going. If I had to pick one or the other, I'd go with the helmet light because you can make sure you have the attention of other drivers just by pointing your head at them. The light is attatched to the front part of the top of the helmet, any blow would slide it right off the top of the helmet. The chance of it going through the helmet is almost completely implausible.

    I won't be giving up my helmet light, but I am experimenting this year with generator/dynamo systems. The typical 6v 3w system could never satisfy us, however I am planning in using multiple cheap Chinese 12v/6w generators connected with rectifiers and possibly backed up with batteries. I've spent some time experimenting with this already and feel I am making good progress. I also have been experimenting with a small permanent magnet motors from a Weed Wacker. A small 6v 3w system has no perceptable effect on our speed, but I expect our new system to slow us down by at least a couple miles per hour.

    Steve M
     


  2. gubaguba

    gubaguba New Member

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    Steve that sounds like some pretty interesting stuff I hope you will keep us informed about your progress. How are you going about connection the generators? Got any photos of progress so far?
     
  3. vonnieglen

    vonnieglen New Member

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    The connections to the rectifier are very straight forward. Each has two leads for your AC input from the dynamo and then two leads for your positive and negative terminals. Unlike a typical dynamo setup you keep the dynamos insulated from the bike frame. The dynamos I purchased have two terminals. You hook the two AC connectors from the rectifiers to the dynamo. You then hook your positive terminals from each rectifier together and the negatives together. You then attatch your light fixtures and multimeter to the positive and negative terminals. I pedal the the test bike mounted in my wind trainer stand to the appropriate speed to determine which wattage bulbs will keep the voltage within the proper limits.

    Despite their 12v 6w rating the Chinese dynamos that I purchased each produce 12v when powering an 11w bulb at 20mph when hooked directly to a bulb, when hooked through the rectifiers they produce 18w at 20mph. Unfortunately they begin to warm up after a few minutes; on the road they will have more wind to keep them cool, but they also slip a bit on the sidewalls, so I have ordered rubber boots to put over the dynamo caps which will increase their diameter and reduce the speed of the dynamos. This should reduce the output which will help keep them cooler, and help reduce the slipping on the sidewalls, hopefully even when it is wet.

    The permanent magnet motor from the Weed Wacker has two wires coming out of it and produces DC power. I have attatched a 2" rubber caster wheel to it's shaft and attatched it to the chainstay so that the wheel rubs on the sidewall. The lower RPM makes it quieter. It produces many times more wattage than a bicycle dynamo, however it weighs significantly more and produces far more drag.

    I am glad there is some interest in this. I will try to take some pictures of my test setup and post a URL to get to them.

    Steve M

     
  4. wiredued

    wiredued New Member

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    About a month ago I made a long bike trip and on the way back stopped at a friends lakeside camp. We got talking and before I new it it was midnight. I opened up and fiddled with my low end Trek light to get the switch working and started down the road. I came to the road I ussually take and noticed it was pitch black no street lights it would have been difficult to walk never mind ride without the light. Because I had no backup light if my $25.00 Trek light failed I continued down the road that had some street lights to get to a main road with more street lights even though it would make the trip longer. After this I decided having a backup system with identical interchangeble parts was the most important feature of a bicycle lighting system.

    I now have a AA Maglite mounted on the handlebar stem using two back to back mineralac clips one is for 3/4" emt(electrical metalic tubing) that is just right to hold the quil type handlebar stem the other is for 1/2" emt to hold the Maglite. I used 1/4 20 nuts and bolts with lockwashers to keep it tight. The back up I keep on my belt or in the underseat bag. Maglites come with extra bulbs in the opposite end creating the needed redundancy(three backup bulbs one backup power source). It works better than my Trek lite and cost the same. If you want more lite there are after market Led kits that throw even more lite but that is an additional $20 for each lite I think the factory halogen is good enough for me. The Maglite also allows you to focus the beam and because it is mounted on the stem I have more room on the top bar hand position.
     
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