sturmey archer 3-speed internal hub motorized bicycle

Discussion in 'Spare Parts, Tools & Product Developement' started by blankbox7, May 2, 2010.

  1. blankbox7

    blankbox7 Member

    My current motorized bike is a 66cc two stroke that I am buying a shift kit for, and have 2 options for the hub:

    ---I have a 7 speed mountain bike cassette and wheel, but it happens to be a little too wide for my beach cruiser frame. The gear range is good, but i dont think i really need 7 closely spaced gears, and skipping gears when shifting can get confusing at times.

    ---I also have an internal 3-speed sturmey archer hub that I salvaged from my friends grandfathers garage (with his permission of course). I know these are reliable when it comes to regular bicycling, but how about motorbicycling? The hub is almost the exact width of my stock hub, so there isnt stress on trying to widen the rear drop outs.

    If anyone has ever tried using an internal hub, or has good knowledge about them, please let me know what you think.

  2. MotoMagz

    MotoMagz Member

    Hi, I asked Jim from SBP and he said some sturmey archer 3-speed internal hub have worked and some have not (blow up). So you might get lucky.

    Good luck MotoMagz
  3. professor

    professor Active Member

    The multi-speed would be stronger. I would not be concerned with stretching the rear triangle, a car jack would work if you have any difficulty making it wider.
  4. SimpleSimon

    SimpleSimon Active Member

    As for the S-A 3 speed hub, I cannot address that. I do, however, have a Shimano 3 speed internal hub serving as the mid-drive on my trike conversion. So far no problems at all with that unit.

    The primary enemy of the internally feared hubs appears to be (despite the immediate idea) to not be torque delivered from the engine, but rather transmitted vibration from the chain loop. With a shift kit (or, in my case, a jackshaft that brings the pedal and power side circuits together just ahead of the mid-drive) that transmitted vibration is somewhat reduced. The hubs are designed to deal with the torque that a 180 pound man standing on the pedals and pulling on the handlebars can generate - which is much, MUCH higher than the torque one of these little engines can deliver.
  5. blankbox7

    blankbox7 Member

    The only reason I am concerned with widening the rear dropouts is because at SBP I read that if the dropouts arnt parallel then there might be problems with a bent/broken axle in the future.

    With the hub I like the fact that it doesnt require much maintainence. Not that Im lazy to fix it, but its one less thing to worry about (the internal hubs look nicer too). I most likely will use the hub, as long as I find the right spoke length for it! I also favor the hub becuase you shift when not pedaling, which removes any mistake of forgetting to down shift before a dead stop.

    Thanks everyone for the help!
  6. KanesKustoms

    KanesKustoms Member

    Heres the rear wheel of my bike ,, I took a Bendix two speed kick back and laced it into a 1936 drop center rim with stainless spokes. I machined out the sproket to fit the hub and mounted it directly to the hub flange with teflon spacers. This set allows you to have two gears the low gear is great for starting then simply kick back to the high gear, A very clean look and very functional. Ive had no problems with this setup

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