Gear ratio - Grubee 2 gearbox

Discussion in 'Transmission / Drivetrain' started by hlombard, May 24, 2008.

  1. hlombard

    hlombard New Member

    One Grubee website lists the ratio of the Grubee 2 Skyhawk gearbox as 4.2:1. Someone heer calculated it at 1.83:1 ???

    I counted the teeth on my gearbox and calculate the ratio as 3.7:1

    Please confirm my calculation:

    Gear 1: 35 / 54 = ratio of 1.54

    Gear 2: 20 / 48 = ratio of 2.40

    Overall ratio = 1.54 x 2.40 = 3.70 ?

    Then you have the reduction from the 11 tooth sprocket to 56 tooth sprocket on the wheel: 11 / 56 = 5.09

    Thats an overall ratio for the setup of 18.85:1

    Can you math-heads please check?

    Thanks
     

  2. ocscully

    ocscully Member

    Your math is correct !

    ocscully
     
  3. HoughMade

    HoughMade Guest

    Yes, you are correct, I have counted mine as well.
     
  4. dnilosek

    dnilosek New Member

    Thought this spreadsheet might help. Please check my math, I'm not an engineer.
     

    Attached Files:

Loading...