Shift Kits?? Confused =\

Discussion in 'Motorized Bicycle General Discussion' started by lolitsdaelan, May 14, 2010.

  1. lolitsdaelan

    lolitsdaelan New Member

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    I know I've been asking a bunch recently, just trying to be as informed as possible :).

    So it seems that a lot of people are pro shift kit. I'm assuming that when the motor is mounted, the standard shifting mechanism of the bike becomes defunct, thus requiring use of a shift kit. Is this correct? Would a shift kit be required if using an internal gear hub?

    If anyone could give a quick rundown of the shift kit that would be great, thanks!
     
  2. Maxvision

    Maxvision New Member

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    The shift kit just re-routes the drive to the pedal sprocket. The kit has a freewheel bearing included that the pedal sprocket bolts to. This prevents your pedals from turning when the motor is engaged but allows you to pedal when it's not or to start your motor (kinda like a kick starter).

    This completely eliminates the second drive chain to the left side of your rear wheel. The actual "shifting" comes from whatever rear hub you're using whether it be internally geared, freewheel or cassette (like on 10 speeds).
     
  3. pj-pirate

    pj-pirate New Member

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    Im no pro at this but will explain what I have. I got a shift kit second hand from a friend that had no mechanical ability. It is a Sick bike Parts kit which they have done their homework! It takes the power from the left side of the bike via chain and jack shafts and drives the chain sprocket on the right side of your bike. The bike now uses the rear sprocket cone and de-railer to give a variety of gear ratios. I enjoy mine for the ability to go off road and climb hills in low gear then hit the hi-way to "light it up" in the upper gears. Managed to clip 54mph topped out(too dam fast for a bicycle but had too see !)
     
  4. lolitsdaelan

    lolitsdaelan New Member

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    Ahhhh I see, so the "shift" in shift kit doesnt exactly refer to the gears themselves. I gotcha, that makes a bit more sense. I also completely failed to notice that the chain from the engine is on the left side.

    So if I don't have a shift kit, the pedals will spin with the motor?
     
  5. Cabinfever1977

    Cabinfever1977 New Member

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    With the engine kit you can still peddal the bike and shift gears,but just when peddaling cause the engine chain drive is on left side.

    If you don't have a shift kit the peddals will not spin with the motor cause the right side of the peddal side wheel has a freewheel that when coasting with the bike or when using motor the peddals do not spin.

    Getting a shift kit for the engine reroutes the left side engine chain to connect to the right side and connects to the peddals and can use the bikes shifting gears just like you do when you peddal.
     
  6. mapbike

    mapbike Active Member

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    Go to this link http://www.sickbikeparts.com/catalog/ and then click on the link that says " CLICK HERE TO WATCH OUR PROMO VIDEO" and you will get a much better idea of how it all works, this is a very simple proccess, and a very good way to set up.
     
  7. lolitsdaelan

    lolitsdaelan New Member

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    Ah ok, having the visuals made it all make sense =P

    Real stupid question, can't you just flip the tire/pedals to the other side and skip the shift kit?
     
  8. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    No, then the sprocket would just freewheel, like when you pedal backwards.

    The kit should more accurately be called a "jackshaft kit", which it is, the shifting part id from your bike parts, not the kit.

    Also without it, you can run the engine and the pedals won't turn. The only thing you use the pedals for it starting the engine, and starting off, before you let the clutch out.
     
  9. Cabinfever1977

    Cabinfever1977 New Member

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    The freewheel on the wheel would be backwards and would just freewheel but even if it spun the correct way your peddals would turn with the motor without the freewheel on the peddals that come with the shiftkit.

    I've never seen a reverse freewheel for a bicycle wheel that spins the oposite way and mounted on the left side,i wonder if anybody makes them. well i googled it and yes they make them,heres a link for the information: http://en.wikipedia.org/wiki/Flip-flop_hub
    But i think they only make small reverse leftside freewheel sprockets(up to 16t i think,u would have to weld a 44t to it), You would still have to have a freewheel on the peddals on left side and would be hard to connect everything together. Plus all of these parts would cost a few hundred dollars.
     
    #9 Cabinfever1977, May 15, 2010
    Last edited: May 15, 2010
  10. Patr1ck

    Patr1ck New Member

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    What about a way to have a sprocket on the left side of the bottom bracket that is chain driven by the motor, that transfers power through the bottom bracket to a sprocket on the right side which drives the rear hub via chain, and a freewheel bearing for the pedals. Hope that makes sense. Basically the same type freewheel crank assembly that is already used with the shift kits today but with an extra sprocket on the left side that is rigidly attached to the right sprocket. It would be a super clean way to utilize the shifting of the bike and look awesome as well. Id buy one.

    Pat
     
    #10 Patr1ck, May 15, 2010
    Last edited: May 15, 2010
  11. lolitsdaelan

    lolitsdaelan New Member

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    Ok, so this should be final question and I'll be squared away.

    I understand that it transfers the chain drive from the left side of the bike to the right side, but what is the actual use that I would gain from having one? From what I've heard if I don't have one I can still use the pedals on the bike, the pedals wont spin with the motor, and I can still shift gears fine.

    I'm still probably missing something, if you can't already tell I'm 100% mechanically illiterate. On that note though, if anyone needs electrical help let me know :)
     
  12. pj-pirate

    pj-pirate New Member

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    basically the advantage of a shift kit is that the motor drives the crank ring which freewheels in one direction---you can still peddle the bike in the normal way when the motor is off--the freewheel will engage when YOU peddle or freewheel letting the engine turn the crank ring thus eleminating the "second chain/sprocket" on the left side of the bike. This enables you to use the bikes gears in a normal fashion with motor or peddling thus not having to be stuck with one gear ratio. This help?
     
    #12 pj-pirate, May 15, 2010
    Last edited: May 15, 2010
  13. Cabinfever1977

    Cabinfever1977 New Member

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    If you ran the drive threw the peddal sprockets starting on the left side, the peddals would turn with the motor,even with a freewheel. but it would work if you removed the peddals and put foot pegs on the bike, would only be good in states that do not require no peddals.
    The engine needs a direct drive to the freewheel then to the rear sprocket on wheel and the freewheel on the peddal sprocket separates the peddals from the drive from engine. You could move everthing to the left side of the bike but would require a few hundred dollars worth of parts.
     
    #13 Cabinfever1977, May 15, 2010
    Last edited: May 15, 2010
  14. Patr1ck

    Patr1ck New Member

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    Could a freewheel bearing be added (like in the shift kits) to one of those tandem bike crank assys as they have a sprocket on each side? If not, does anyone feel like designing one?

    Pat
     
  15. Cabinfever1977

    Cabinfever1977 New Member

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    You're better off buying a shiftkit from sickbikeparts.
     
  16. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    Without a shift kit, your engine drive is a single speed, so your "I can still shift gears fine" statement only applies to leg power NOT engine power. You probably should see or get a regular bike engine kit. As soon as you bolt the left side engine kit sprocket to your spokes, you will understand you can't use your bike gearing with the engine.
     
  17. lolitsdaelan

    lolitsdaelan New Member

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    Gotcha, it must be one of those things I have to experience :p

    I picked up the bike this weekend, and should be ordering the engine in the next few days.

    I can't wait!

    Thanks for all the help guys!
     

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