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  1. #1
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    Crank on Bottom bracket spacing?

    Hello,
    Just got into bike building and already have run into trouble: the Compy Veloce crank (recently purchased) does not seem to fit properly onto the Sugino bottom bracket (came with the frame). The right side clearly is further away from the frame than the left side.
    Is the spacing on the right side too great?


    Thanks for the help,
    Mitch

  2. #2
    motovation frankenmike's Avatar
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    It does look a little wide on the drive side. Does the middle of the chainrings line up near the middle of the rear cluster? If so, it's probably fine.
    Last edited by frankenmike; 10-11-08 at 07:57 PM.

  3. #3
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    Quote Originally Posted by frankenmike View Post
    It does look a little wide on the drive side. Does the middle chainring line up near the middle of the rear cluster? If so, it's probably fine.
    Sadly I don't even have my rear cluster set up yet.
    Even so, wouldn't this be "stressful" on my body because my feet wouldn't be symmetrical?

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    motovation frankenmike's Avatar
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    I suspect that it won't be noticeable, but the only way to be sure is to ride it.

  5. #5
    slow as I ever was Ex Pres's Avatar
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    With a photo I could make the distance look right, too close, or too far. You can't really tell from a photo.

    The only way to know for sure is to measure. Take these three:

    1. Diameter of your down tube. (Should be 1 1/8", 1 1/4", or 1 3/8")
    2. Distance from the edge of your down tube to the inner/smaller chain ring (in mm)
    3. Same from DT except to outer ring. (also in mm)

    Get back to us with those and we can give you some results.
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  6. #6
    Insane Bicycle Mechanic Jeff Wills's Avatar
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    Quote Originally Posted by thyvillageidiot View Post
    Hello,
    Just got into bike building and already have run into trouble: the Compy Veloce crank (recently purchased) does not seem to fit properly onto the Sugino bottom bracket (came with the frame). The right side clearly is further away from the frame than the left side.
    Is the spacing on the right side too great?

    Thanks for the help,
    Mitch
    I'm less concerned with the spacing and more with the fact that you're putting an ISO taper crank on a JIS taper spindle. This should work, but the crank will sit farther out on the spindle than if you had the correct ISO BB installed. Here's what the late, great Sheldon Brown said on the subject: http://www.sheldonbrown.com/bbtaper.html

    Jeff
    Jeff Wills

    All my bikes.

  7. #7
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    Quote Originally Posted by Jeff Wills View Post
    I'm less concerned with the spacing and more with the fact that you're putting an ISO taper crank on a JIS taper spindle. This should work, but the crank will sit farther out on the spindle than if you had the correct ISO BB installed. Here's what the late, great Sheldon Brown said on the subject: http://www.sheldonbrown.com/bbtaper.html

    Jeff
    Oh... I see: so I bought the wrong kind. Thanks very much for your insight and link, I'll stop my fruitless tinkering and be returning this ASAP.

  8. #8
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    Quote Originally Posted by Bob Barker View Post
    With a photo I could make the distance look right, too close, or too far. You can't really tell from a photo.

    The only way to know for sure is to measure. Take these three:

    1. Diameter of your down tube. (Should be 1 1/8", 1 1/4", or 1 3/8")
    2. Distance from the edge of your down tube to the inner/smaller chain ring (in mm)
    3. Same from DT except to outer ring. (also in mm)

    Get back to us with those and we can give you some results.
    Theoretically, what could be learned with these numbers?

  9. #9
    Senior Member DannoXYZ's Avatar
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    Depending upon the vintage of the frame, the Sugino BB could be for an older crankset that was designed for a spindle with a longer right side.

    Another way to test is to place the crankarm parallel to the chainstay and measure the gap between the end of the crankarm and the chainstay. The difference between the two sides should be less than 5mm. I can feel a difference larger than that, but below, it's not noticable at all.

    You can also make up for the difference with some washers on the pedal-spindle to space one side out a little more.

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