How do you calculate ring sizes for use with tires and beadbreakers?Last Updated: June 05, 2018
The following table is a listing of available tire rings for use on tires. To determine the ring size you require, add 0.55 inches to the wheel maximum O.D., then round this number to the next higher whole number.
EXAMPLE: For a wheel O.D. of 11.62 inches, the calculation is as follows:
11.62 inches (Maximum wheel O.D.)
+ 0.55 (Tronair standard size factor)
Rounding to next whole number gives 13.
A "sizing" number of 13 dictates a Z-106X-13 tire ring