Travelerajm, may I ask what is the SI unit for the individual variables for calculating effective mass? I got 0.1556??? M= grams? or kilos? b= cm L= cm R= cm SW= kg/cm2 For excel, would this be right? Effective Mass=M/(1+(M*(POWER(b,2)/Ic))) Ic=SW-M*(POWER(b-10,2)) Which of the 3, MgR/I, MR^2 or Effective Mass should have the highest importance? Which should I achieve first? Lastly, thanks for the insightful post!