8 Repeat the process on the front wheel and compare your measurements to the front wheel on the opposite side. The distance between the string and the wheel doesn’t have to be equal. For example, the string on one side can be 8 inches from the tires while it’s 10 inches on the other. That’s OK, what you want to be able to compare is the distances from front to back. If you want to know the track width, simply subtract the distances from the strings to the center of the tires on either side from the total distance between the two strings. What you’re left with is your track width.