Downhill bikes which are meant to withstand the abuse of drops and rock gardens are typically equipped with tires up to 2 5 wide.
Mountain bike tire width sizes.
Mountain bike tire size and width.
Typical mountain bike tire.
These sizes can be thought of as a sort of shorthand for decimal sizes each with a corresponding iso measurement.
Trail and all mountain bikes will have tires in the 2 25 to 2 4 width range.
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.
26 inches 27 5 inches and 29 inches.
This varies from 1 6 to 2 5 inches.
Tires are also measured in width.
Once you ve identified your tire diameter 29 27 5 or 26 you ll want to dial in your width.
Check your tire s sidewall the numbers there indicate your tire size roughly its outer diameter and its width but not always in that order.
Some special tires can even be wider up to 3 inches with some models.