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  1. #1
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    StringBike. No chain, just strings.



    From Rohloff to Pinion to Strings. :-)

    Appears to have 19 speeds and can be shifted while stationary. Total range of 250%. Wide Q-factor. No dishing needed for the wheels. Due to symmetry of drivetrain, perfect alignment of drive components. The drive does not require lubrication or maintenance and uses a polyethylene rope.

    Left and right sides do not need to use the same gearing. Therefore if one has a disability, a bike could be tailored to meet asymmetric strength requirements.



    How It Works
    http://www.stringbike.com/principle-of-operation

    How To Change Gears
    http://www.stringbike.com/Change%20of%20gears

    How Efficient Is It?
    http://www.stringbike.com/Efficiency%20of%20the%20drive

    How Does It Feel Compared to a Chain Drive?
    http://www.stringbike.com/Driving%20curves
    http://www.stringbike.com/Smooth%20driving
    Last edited by puppypilgrim; 09-22-10 at 11:45 AM.

  2. #2
    Senior Member
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    Intriguing! I'll be interested to hear the engineer types on this board weigh in.

  3. #3
    Senior Member mustachiod's Avatar
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    in before the engineer debate
    Quote Originally Posted by powers2b View Post
    BF does not have the answer to what you will be happy with.

  4. #4
    Senior Member Fast Cloud's Avatar
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    Those cams make it look sort of like a compound bow. I'll pass.

  5. #5
    jur
    jur is offline
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    Very interesting.

    As always, I am curious about the efficiency numbers (not wordy descriptions). As usual, there are no numbers.
    It looks like it has the capability to be made really light. The current design seems heavier than a derailer system. The rear hub needs work for this.
    Looks like it could be almost completely dirt-proof.
    It looks like it needs a special frame.
    It uses lots and lots of extra bearings.
    It uses far fewer bearings than in a chain.

    The inventors need to show not innovation but a clear improvement on what is already available, from efficiency, cost and weight POVs.
    My folding bike photo essays www.dekter.net/

  6. #6
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    I don't know if its a better mousetrap.

    Website says no lubrication or maintenance is needed. Seems to have complex moving parts to me. And complex to me is not so good but what do I know? The pedaling feel is not like a chainring. More of a lever action. Nothing wrong with the innovation I suppose. The only thing that would need replacing over time is the string\rope ad bearings. The hub would last the life of the bike.

  7. #7
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    Thank you. Good share!

    I've got a few questions though.
    Are'nt there springs in the rear hub to return the strings and crank to the pre-power delivering phase?
    And won't this "return" tendency zap rider energy by acting in the opposite direction of rider applied moment?
    2009 Curve XRF8w
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  8. #8
    rhm
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    multimodal commuter rhm's Avatar
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    1. Seems to me I saw something very like this in a transportation museum in Germany... on a bike from the turn of the last century.


    2. And it folds... how?

  9. #9
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    Quote Originally Posted by rhm View Post
    1. Seems to me I saw something very like this in a transportation museum in Germany... on a bike from the turn of the last century.
    Which just goes to show once again that all major innovations in bicycle design--including ones we think of as very modern--were originally developed in the 19th century: folding bicycles, internal gear hubs, shaft drives, etc.

  10. #10
    Senior Member Smallwheels's Avatar
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    In all of the videos with someone turning the cranks by hand the motion looked very jerky. I think belt drive with an internal gear hub gives the same advantages without so many parts.
    Smallwheels

    Take my stuff, please. I have way too much. My current goal is to have all of my possessions fit onto a large bicycle trailer. Really.

  11. #11
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    True Smallwheels. Simpler and cheaper. For me though, I think a singlespeed chain drive is still tops for ease of use and maintenance.

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