How To Read Mountain Bike Tire Sizes

Georgena terry explains what those numbers molded into the sidewall of your bicycle tire mean.

How to read mountain bike tire sizes. These sizes can be thought of as a sort of shorthand for decimal sizes each with a corresponding iso measurement. Widths range from 1 9 to nearly 5. Mtb wheels in particular can be further categorised by 26 inches 27 5 inches and 29 inches. A cross country bike will have tires in the 1 9 to 2 25 width range.

You can find this measurement on the side wall where you should see two numbers separated by an x ie. Outer tire diameters can be 26 27 5 or 29. 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. While you can find a variety of bikes with wheel sizes ranging from 16 to 27 5 inches the most common sizes include 26 inches 27 5 inches 29 inches and 700c.

To confuse matters further all tyres use the european tyre and rim technical organisation etrto system so for a road it would display 622 x nn with the nn value indicating the tyre width which is the same as 700 x nn. Mountain tire sizes 26 twenty six inch is the most commonly used size for modern mountain bikes and is also used on many hybrid or utility bikes. Read the size carefully. A hybrid of road and mountain tires cyclocross tires are labeled as 700c and have widths indicated in millimeters like road bikes yet are knobbie like mountain bike tires.

The example sizes below give you a rough guide for tire sizes on different types of bikes today. It s actually the same bead seat diameter as 700c tires but most 29 tires are simply too wide and tall to fit 700c wheels. Sizes written as decimals such as 2 75 are different than sizes expressed as fractions such as 2 3 4. There are multiple tires to consider and it s important to understand tire size.

Whether you are mountain biking on dry trails in utah or through the waterfalls of iceland having the right tires is crucial for the best riding experience. Finding the right inner tube depends on the size of the tires on your bike. Once you ve identified your tire diameter 29 27 5 or 26 you ll want to dial in your width. Tires are essential to mountain biking the type of terrain you ride and they can have a big impact on your riding experience.

There are a myriad of wheel sizes for road mtb touring and children s bikes. Trail and all mountain bikes will have tires in the 2 25 to 2 4 width range. 29 the 29er another popular size for mountain bike wheels and tires.