Typical mountain bike tire.
Mountain bike tire width sizes.
These sizes can be thought of as a sort of shorthand for decimal sizes each with a corresponding iso measurement.
This varies from 1 6 to 2 5 inches.
The sizes you commonly see for mountain bike wheels like 26in 27 5in and 29in all refer to the outside diameter of the wheel with the tire fully inflated.
Tires come in three diameters.
A cross country bike will have tires in the 1 9 to 2 25 width range.
Once you ve identified your tire diameter 29 27 5 or 26 you ll want to dial in your width.
Tires are also measured in width.
2 2 and 27 5 indicate a tire that has a width of 2 2 and an outer diameter of 27 5.
26 inches 27 5 inches and 29 inches.
Trail and all mountain bikes will have tires in the 2 25 to 2 4 width range.
Some special tires can even be wider up to 3 inches with some models.