This is Gen IV Specific, but the measuring procedures work for any scooter you want fatty the rear.

Ice Bear Icebear Maddog Gy6 150cc 50cc Fatty Wide Wheel with Stretched Tire. 12x8, 12 x7 or 13x8, 13x7 Wheel. 130/70-12 or 140/70-12 Tire. How to calculate Offset, Backspace and Rim Size and How to Stretch the Tire.


How to Change Your Tire    • The Black Art of Changing Mini Bike T...  

Matching Front Stretch Tire    • Fatty Stretched Front Tire and Wheel ...