WARNING!!! Increasing the speed of a unit could cause fan and motor failure. If you are unaware of the outcome that sheave changing can make then you should hire a professional to do this work for you. BK Single Groove Size a new Belt?? "A" BELT "AX" BELT "B" BELT "BX" BELT "C" BELT "CX" BELT "2L" BELT "3L" BELT "4L" BELT "3VX" BELT "5VX" BELT "8VX" BELT Design CFM: Actual CFM: Fan Sheave: Diameter NEW: Sheave Size Dia: New Model #: Bore Sizes: Directions:Click inside each white box above to enter your numbers. If any number is above 1000 do not add the comma "," as in 10,000 cfm. When all of the information is correct in all three boxes then left click the Calculate button. home | personnel | belt sizer | sheave sizer | calculator | calc. area | convertions | tutorial | comments | message board