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  1. #1
    Senior Member JasBike's Avatar
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    I'm confused about bike comp calibration...

    i have a Cat Eye Enduro 8...



    i mounted the magnet/sensor, set the circumfrence... but what i dont understand is how does the computer know where the magnet/sensor are located on the wheel? wouldnt the readings be different if the magnet/sensor was on the very bottom of the wheel vs. at the very center of the spokes?




    or am i just being insanely stupid and missing something..

  2. #2
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    One roation of thee wheel is one rotation of the wheel at any point. So it does not matter where the sensor is positioned.

  3. #3
    Senior Member JasBike's Avatar
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    how exactly do the comps work..

  4. #4
    A Heart Needs a Home Rich Clark's Avatar
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    The computer counts revolutions of the wheel, and computer has a clock.

    If it knows the circumference of the wheel, it knows the distance that wheel covers in one revolution.

    If it knows how long it took to cover that distance, if can calculate your speed.

    That's it.

    RichC
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  5. #5
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    It can tell how fast the wheel is turning. The manget part that you put on the spokes only fits in one position on the wheel. If you try to push it down any further or up more it will bend the spokes. Then you enter into the computer what size your wheel is and it's programmed to know how many times the wheel rotates a second

  6. #6
    Senior Member JasBike's Avatar
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    it.. bends spokes?
    If you don't fall, you're not riding hard enough.

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    Ride it like you're breakin' outta jail.

  7. #7
    Aquatics Master AquariaGuy's Avatar
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    Like what Rich said. All it needs is circumference and the rest is basic physics.
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    Wickedly lickety shot,
    Spickety spickety split lickety! :D

  8. #8
    Senior Member JasBike's Avatar
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    but the speed at which the magnet makes a full rotation would vary depending on its position the wheel...

  9. #9
    Oh God, He's back! 1oldRoadie's Avatar
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    remember you put a number into your computer when you set it up? It was something like 2012 or some other four digit number. well that number is the length around the outside of the tire. That is why they have different number for different wheels.

    And that magnet just counts the RPM or wheel speed not the distance it is going.
    I can't ride and Frown!

  10. #10
    Senior Member JasBike's Avatar
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    Originally posted by 1oldRoadie
    remember you put a number into your computer when you set it up? It was something like 2012 or some other four digit number. well that number is the length around the outside of the tire. That is why they have different number for different wheels.

    And that magnet just counts the RPM or wheel speed not the distance it is going.


    i get it...





    btw nice avatar

  11. #11
    Senior Member JasBike's Avatar
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    so the magnet/sensors position on the wheel doesnt matter?

  12. #12
    I am a lonely visitor RegularGuy's Avatar
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    Originally posted by JasBike
    so the magnet/sensors position on the wheel doesnt matter?
    Not at all. The magnet will pass the sensor once per wheel revolution whether it is mounted at the rim or the hub.
    Religion is a good thing for good people and a bad thing for bad people. --H. Richard Niebuhr

  13. #13
    A Heart Needs a Home Rich Clark's Avatar
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    Originally posted by JasBike
    so the magnet/sensors position on the wheel doesnt matter?
    No. It counts revolutions of the wheel. The speed is calculated based on time divided by number of revolutions, with the circumference number telling the computer how far you go per revolution.

    If a wheel were 600 inches in circumference and it rotated 60 times in one hour, you would be going 10 inches per hour.

    RichC
    Training: 2002 Fuji Roubaix Pro (105 triple)
    Commuting/Daytripping: 2001 Airborne Carpe Diem (Ultegra/XTR, touring wheels)
    Commuting/Touring: 2000 Novara Randonee (Sora/Tiagra/LX, fenders, lights)

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