In reading several threads about wheel diameters, back-set, and offset I need enlightenment. I know where the diameter is measured and how to measure the back-set, or back space, but I have never heard of the offset. I plan to change the original 3 sp and torque tube in my 54 3100 to an OD trans plus open drive line using fairly narrow 16" wheels. Before I buy anything I need to understand the vocabulary