Double freewheel? Do they exist?

Discussion in 'Electric Bicycles, Trikes and Recumbent Bicycles' started by jlatshaw, Jul 25, 2013.

  1. jlatshaw

    jlatshaw New Member

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    Hello,

    So I'm building an ebike, and I have an electric motor that I will hook up to my rear sprocket of my bike with a chain so that I'll have a pedal assist relationship going on.

    In this situation I will always have to be pedaling, and if I ever want to turn my motor off (or my batteries run out) I'd like to pedal on my own without spinning my motor unnecessarily which I would rather not do.

    So I am looking for a solution to this problem that will allow me to be able to have: full pedal (without spinning my motor), full motor (without moving my pedals), or pedal and motor assisted.

    I believe that if I have a "Double freewheel" or "double roller" on my rear sprocket that this will fix the problem for me. What I mean by a double freewheel is to have some sort of freewheel that I can have a chain from my pedal on one sprocket and a chain from my motor on another sprocket and have them independent of each other (either can spin while the other is stationary or they can spin together).

    Does something like this exist? What would be it's rightful name? Any google helps?

    Thanks for any help,
    -James
     
  2. jlatshaw

    jlatshaw New Member

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    I was doing some research, do you think a flip flop hub would work?
     
  3. bigbutterbean

    bigbutterbean New Member

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    If you are connecting your engine to the pedal side, a front chainring freewheel like what the sbp shift kit uses is your answer. If you're connecting the engine to the non-pedal side, there used to be a deal called the HybriPed sprocket, which had a pin in it and if you pulled the pin out, the sprocket would freewheel. At least that's how I think it worked. I dont know if they are still around or not.
     
  4. Nashville Kat

    Nashville Kat Active Member

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  5. jlatshaw

    jlatshaw New Member

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    I found this on youtube:

    http://www.youtube.com/watch?v=EZHjs7u_fVY

    Something like that would satisfy my end goal, but I'm pretty sure that guy had this made custom, so I don't know if they exist in the real world.

    I'll keep searching, you guys got me going in the right direction.

    Thanks,
    -James
     
  6. jlatshaw

    jlatshaw New Member

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  7. middriveebike

    middriveebike New Member

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    Mid Drive Conversion kit is definitely your answer.

    450W 48V Brushless Mid Drive Ebike Conversion Kit with Mudguard

    The front chainring is integrated with a one way clutch that only engage when you are pedaling.

    The driving gear on the motor is also one way clutch that becomes a free wheel when you pedal. So you won't be dragging the motor.
     
    #7 middriveebike, Sep 25, 2013
    Last edited: Sep 25, 2013
  8. LR Jerry

    LR Jerry Active Member

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    Staton Inc shiftkit is a double freewheel setup. The engine chainring and the peddle chainring(s) operate independently of each other. David's kits have pull start engines therefore you don't have to bump start them. That's why SBP shiftkits only use a single freewheel so you can bump start engines without pull cords. Satin Inc also sells flip flop hubs. You'd need a left side freewheel.
     
    #8 LR Jerry, Sep 25, 2013
    Last edited: Sep 25, 2013
  9. maurtis

    maurtis New Member

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    Staton makes a hub with left hand freewheel threads and right hand freewheel threads: http://www.staton-inc.com/store/products/Rear_36_Hole_12_gage_Hub_Left_and_right_hand_threads-859-35.html

    They also have a left hand thread freewheel clutch to bolt various tooth sprockets to.

    My Mongoose CX24V450 uses a similar setup with the motor driving a 16T freewheel on the left side and the pedal chain driving the right. I tried finding a replacement hub like that one to use on another build, but since the bikes have been out of production for years, they do not seem easy to come by. And that Staton one at $90... The BGF hub is priced right, but I have no idea of the quality.

    Good luck!
     
    #9 maurtis, Sep 25, 2013
    Last edited: Sep 25, 2013
  10. LR Jerry

    LR Jerry Active Member

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    I personally have a Staton Inc hub and Shiftkit. Both are well wroth it. Neither has failed on me yet.
     
  11. chmn22s

    chmn22s New Member

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  12. chmn22s

    chmn22s New Member

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    @ maurtis I can't find the hub you linked to. it's a very old link :p
    still searching
     
  13. chmn22s

    chmn22s New Member

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    I think this is maybe what I was interested in originally. freewheel sprocket and HD drum brake axle kit from bicycle-engines
     
  14. wheelbender6

    wheelbender6 Active Member

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    You might be able to find a dual freewheel rear from an older Currie electric kit.
     

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