sprocket diameters made easy for Motorized Bicycles

Discussion in 'Instructions for Building and Repairing Motorized ' started by diceman2004, Feb 9, 2010.

  1. diceman2004

    diceman2004 New Member

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    for anyone who needs to figure out the diameter of any given sprocket

    simply multiply the pitch of the chain , by the number of teeth on the sprocket
    then divide by 3.14

    Number 35 Chain: Pitch = 3/8" | Roller diameter = 3/16" | Roller width = 3/16" | Pin diameter = 1/8" | Tensile = 2,100

    Number 41 Chain: Pitch = 1/2" | Roller diameter = 5/16" | Roller width = 1/4" | Pin diameter = 1/8" | Tensile = 2,000

    Number 40 Chain: Pitch = 1/2" | Roller diameter = 5/16" | Roller width = 5/16" | Pin diameter = 5/32" | Tensile = 3,700

    eg: - whats the diameter of a 72 tooth sprocket , that uses number 41 chain ?
    Number 41 Chain: Pitch = 1/2"
    .500 x 72 = 36
    36 / 3.14 = 11.464 diameter

    NOTE : This is the diameter at the center of the chain roller , so you can also use this number accurately in calculations .

    The outside diameter of the actual sprocket will be roughly 3/8 - 1/2 bigger at the tips of the spurs .
     

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