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  1. #1
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    A recumbent electric bike?

    This question is about an electric bike, but it is much more so about frames than it is about the electrical components. I want to buy a bike like this:

    ebike.jpg

    If I were to move the crank foward about 12" to the base of where the battery is now, what would be the effect on pedaling this bike? I would lower the seat about 5" so the legs would still reach the pedals My goal in doing this is to lower the center of gravity, reduce wind resistance and create some free space where the crank now is for a critical component. The picture I have in my mind is a bike that is halfway between a recumbent and an upright.

  2. #2
    Senior Member PaPa's Avatar
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    Quote Originally Posted by pengyou View Post
    If I were to move the crank foward about 12" to the base of where the battery is now, what would be the effect on pedaling this bike? I would lower the seat about 5" so the legs would still reach the pedals My goal in doing this is to lower the center of gravity, reduce wind resistance and create some free space where the crank now is for a critical component. The picture I have in my mind is a bike that is halfway between a recumbent and an upright.
    You'd be wise to forgo the modifications and begin with a clean-sheet.

    * Moving the cranks isn't an issue. However, lowering the seat would place the handlebars chin high - can you live with that?

    * The optimum location of the laden vehicle's CoG (talking single-track vehicles only), is typically well above axle height, and often closer to the top of the wheels. 'Tis only the multi-track vehicles that gain from low CoG.

    Have you seen theses?:

    http://www.atomiczombie.com/main.aspx?click=plans

  3. #3
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    Thanks! I hadn't thought of the handlebars. I did a quick estimate/measure...I think I may be able to get by without lowering the seat an appreciable amount. It is already about 3-4" too low for comfortable pedaling - I just got the bike and have not adjusted the seat yet. My concern was the angle of pedaling. The recumbents are mostly a horizontal pedal stroke, i.e. parallel to the ground. If I moved the crank, the stroke would be 45% to the ground. I was concerned about the ergonomics of the move.
    Last edited by pengyou; 05-12-11 at 05:43 PM.

  4. #4
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    Check out crank forward bikes like Rans.

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