Tires

[Rachika Garcia]

From what point do you measure the diameter of a tire. Is it from the outer edge of the tread or is it from the plastic part of a pneumatic tire?

[Leav]

The "plastic edge" is known as a hub and the wheel diameter includes the tire.

If buying online or without the ability to measure, check with vendor for sprcific measurments before buying, if it is of a critical nature.

-Leav

[EricH]

I believe it's from the outer edge of the unmodified tire. So an 8" Skyway would have tread with its outer edge at 8", and be classified as such even if you grind all the tread off.