sturmey archer front dynamo debaucle?!

Discussion in 'Motorized Bicycle General Discussion' started by halfevil333, Jul 9, 2010.

  1. halfevil333

    halfevil333 New Member

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    does anybody know if installing a front dynamo hub "backwards" or upside down, if you will, would affect it's ability to generate electricity?
    ...the brakes work fine by the way, and the bulbs are new...?!?
    trying not to catch a ticket, not to mention night riding in florida is scaaaaary w/no lights!!!
     
  2. BarelyAWake

    BarelyAWake New Member

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    o_O

    Just a dynamo can run forwards or backwards w/o any problem... but who knows what kinda sneaky stuff they've hidden away in there?

    ...but - I jus' went and gave my X-FDD a spin ta see, only to learn I've burned out my driving light lol Anyhoo - after replacing that bulb (I've a high beam too) it does indeed work just fine spinning backwards... but I gotta ask, why would you mount it reversed? Dare to be different? :p


    edit: I see you've said "bulbs" which I'll infer means you're running more than just one 6v lamp bulb, which surprisingly the X-FDD doesn't like very much as it doesn't actually put out a lot in the way of amperage. As I'm running a taillight, driving/running light as well as a headlight/high beam I've switched to the LED replacement flashlight bulb Walmart sells, designed to operate at any voltage between 3 & 12v it works well... tho a touch more than I'd like to pay for a flashlight bulb normally lol

    At the moment I'm running the LED in just the taillight... but as the driving light jus' quit (cheapo incandescent) I guess I'll be gettin' another heh
     
    #2 BarelyAWake, Jul 9, 2010
    Last edited: Jul 9, 2010
  3. ferball

    ferball New Member

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    I may be wrong on this so if I am you electrical geniuses please be gentle...but if the dynamo produces ac current (which is doubtful for a bike) then either direction won't make a difference, but LED bulbs won't light on AC power without extra stuff. If it is a DC dynamo I believe running it backwards would just change polarity, again no problem except that with LEDs do care which direction the current runs so you would have to install them backwards as well...That is my understanding of things, but I am an not an expert.
     
  4. bairdco

    bairdco a guy who makes cool bikes

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    if you run it backwards, i think that means you have to put your taillight in the front and your headlight in the rear. dunno how the turn signals would work...:)
     
  5. Kevlarr

    Kevlarr New Member

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    LEDs will run on either AC or DC they just don't last as long running on AC. The multi color LEDs they use in electrical testing equipment that show up one color for +/- another for -/+ and a third color for AC is just a single led with a double diode inside, run it on AC and both diodes light making the third color.
     
  6. halfevil333

    halfevil333 New Member

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    ok, first, thanks for the response,
    second, yes my headlight has two bulbs in it, a high and low beam.
    it's the fancy chrome bullet style I ordered from a lowrider bicycle site, and there is a taillight,
    both the low-beam &taillight are extremely small like 3v...
    as for the mounting, I'm rocking the bent springer forks, for that sweet low-low look, and that just seemed to work better for me?...
     
  7. halfevil333

    halfevil333 New Member

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    "I may be wrong on this so if I am you electrical geniuses please be gentle...but if the dynamo produces ac current (which is doubtful for a bike) then either direction won't make a difference, but LED bulbs won't light on AC power without extra stuff. If it is a DC dynamo I believe running it backwards would just change polarity, again no problem except that with LEDs do care which direction the current runs so you would have to install them backwards as well...That is my understanding of things, but I am an not an expert.">>>ferball...sorry forgot to quote so I cheated;)


    yes, thank you, I too understand the basics of electricity. but, we're talking bout cheep chinese **** w/a single wire running to either light, which kinda confuses me as well, unless the current were somehow running through the frame to complete a circuit?
     
    #7 halfevil333, Jul 9, 2010
    Last edited: Jul 9, 2010
  8. halfevil333

    halfevil333 New Member

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    yous a funny guy!
    don't think the coppers in Florida have the sense of humor for such shennanigans though...laff
     
  9. Kevlarr

    Kevlarr New Member

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    If it has a single wire coming from the dynamo the frame is the ground but you'll have to check with a meter to see if ground is positive or negative.

    My tail light clamps to the seat stay and it has a set screw in the clamp to dig through the paint and get a good ground.
     
  10. GeneFiorot

    GeneFiorot New Member

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    All the jokes aside and the electrical engineering experts aside my SRAM Dynamo Hub came with a specific direction for turning.
     
  11. BarelyAWake

    BarelyAWake New Member

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    Now I'm a lil confused o_O

    I thought we were talking about the Sturmey Archer Dynamo front hub? Which would be somewhat costly, Taiwanese, actually quite well made & both a positive and negative connection?

    What model are you talking about? the X-FDD?
     
  12. halfevil333

    halfevil333 New Member

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    I meant the headlight/taillight set I am using....
    and yes I am running the x-fdd, would you mind posting a pic of your wiring and maybe it will give me a better idea of where I'm going wrong?...
     
  13. halfevil333

    halfevil333 New Member

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    ok, just replaced the wiring, and the bulbs...my dumbazz had a 12v. bulb in a 6v. system, however, all I could find was a 7v.3w. which is closer...come nightfall I'll tell you whether or not it worked, if not I'll just get a longer brake cable and flip the beast over?
     
  14. halfevil333

    halfevil333 New Member

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    do you think you could give me a part number on that bulb?
     
  15. BarelyAWake

    BarelyAWake New Member

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    [​IMG] [​IMG]

    Postin' pics of my wiring doesn't help ya much as I've been sneaky and hidden it all away as much as possible - but I believe that if yer looking at the lil plug side, the right-hand port is the ground/negative (if plugin on hub is facing up). While incandescent bulbs don't care about such trivialities, LED bulbs can be picky heh

    Bulb part # - 'Nite Ize' D&C LED Upgrade - part# LRB-07-PR
     
    #15 BarelyAWake, Jul 11, 2010
    Last edited: Jul 11, 2010
  16. halfevil333

    halfevil333 New Member

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    did you use copper tubing to stash the wires? thats sweet!
    well the neck on my girl stripped out last night as I was riding over a slippery azz bridge!
    scaaaaary! good thing I had a co-worker following me due to the no light situation...
    looks like I'll have the time to rearrange everything now anyways...

    here's a couple 'o' pics. frm a few days ago
     

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    #16 halfevil333, Jul 11, 2010
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  17. WayneC

    WayneC New Member

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    You guys with the S/A front hub, how do you find the braking with those? I have the X-FD for a while
    and the brake is merely adequate. I have heard people rave about the braking and some of the bike
    forums claim they're about as good as disk brakes! I'd put mine more on par with basic caliper brakes.
    It's Okay, but I expected better from some of the reading I did. OR maybe its just all the weight I'm
    trying to stop. IDK. I'm thinking about the X-FDD for another build but REALLY need good braking for it.
    WC
     
  18. azbill

    azbill Active Member

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    wayne,,,
    I have had an X-FD for over 4 years (approx 15-16,000 miles)
    I have always been very pleased with how well mine works
    for a while, when I first got it, it was the only brake I had (my old Deviate chopper - r.i.p.)gallery384
    I pull a trailer with my grandkids, and NEED good brakes with such precious cargo ;)
    they haven't given me any reason to worry so far :)
     
  19. halfevil333

    halfevil333 New Member

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    ok, just tried the white wire hook-up suggestion, which would kill my motor if I try to turn the lights off, by still did nothing when I try to turn them on...so?
    this means I no longer think there's anything wrong w/my dynamo, however, I REALLY CAN NOT FIGURE OUT WHERE ELSE THE PROBLEM MIGHT BE?
    what guage of wire are you using BARELYAWAKE? -this is the only thing I can think of... the system came w/very thin stranded wire, I've tried both solid & stranded 18guage to no avail, thinking maybe wire to heavy to carry current?
     
  20. BarelyAWake

    BarelyAWake New Member

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    halfevil333 - Yer prolly gonna lol - but I'm using USB cord for wiring, if anything the gauge is on the small side which would increase resistance but it seems to work well enough & I liked it for aesthetic reasons as it's perfectly round and fits sweet in that copper tubing (expensive, but I've a bunch of it anyway).

    I'm not sure what the problem might be with your setup man, all I can suggest is propping the bike up so you can freely spin the wheel and test... if you don't have a mutlitester then ya need one particularly for testing continuity, there only like $12 for a cheapo.

    Yer gonna have less luck with the engine's white wire than the hub as it puts out even less juice particularly anywhere near idle... but from what you're sayin' I wonder if you might have swapped things around somewhere? It "should" kill the engine when you try to turn the lights on at idle w/the white wire (lights rob all power frm spark)... and with the hub - I dunno if you're trying to use a frame ground but I wouldn't, the forks aren't the most reliable ground so I ran positive and negative wires to everything. Last but not least - 6v is about all the hub can handle so of you've not gotten a 6v bulb (battery lamp for camping) then mebbe that's all the problem is.

    Try the basics if you've not already - just one bulb with a short test lead of both a negative and positive hooked directly to their ports on the hub and give it a spin. I wish I could help ya more man :(


    WayneC & azbill - while I really do like my drum brakes & I think them far better than calipers, I don't think they're quite as good as quality disks for extreme riding. My interests were reduced wear, wet weather riding & multipurpose hubs (3sp & genny) ;)
     
    #20 BarelyAWake, Jul 12, 2010
    Last edited: Jul 12, 2010

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