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  1. #1
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    Noisy dynamo hub

    I bought and fitted a Dahon Joule II hub last week. Have now gone out on bike (20" Dahon folder) and the hub seems to be making quite a noise at higher speeds. Normal? A case for returning to supplier?

    Martin

  2. #2
    Randomhead
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    is it the hub, or hub/light combination?

  3. #3
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    noisy dynamo hub

    Quote Originally Posted by unterhausen View Post
    is it the hub, or hub/light combination?
    Not being a techi ... would that meant that the hub might be generating too much/too little power which increases at high speed and doesn't have anywhere to offload it to (as the lights might not take all the power? But if that was the case, wouldn't it just blow the diodes/bulbs?

    I'll try riding it with the wires disconnected and see what happens.

    Martin

  4. #4
    Senior Member mulveyr's Avatar
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    Quote Originally Posted by Foldingmart View Post
    Not being a techi ... would that meant that the hub might be generating too much/too little power which increases at high speed and doesn't have anywhere to offload it to (as the lights might not take all the power? But if that was the case, wouldn't it just blow the diodes/bulbs?

    I'll try riding it with the wires disconnected and see what happens.

    Martin
    I'm not familiar with that particular hub, but it's semi-common for dynohubs to vibrate at higher speeds, especially with a load connected. My Shimano hub, for example, vibrated between 18MPH and 21MPH with an IQ Cyo light, but never above or below that. It's not a matter of "offloading power", it just happens that like any mechanical device, there are resonant frequencies where you get behavior like that. In regards to noise, I never had any discernable noise from the hub itself, other than the effects of the vibration.

    Sometimes the light changes things, too. After installing a Luxos U light, I get no vibrations at all.
    Knows the weight of my bike to the nearest 10 pounds.

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