Cyclocross Tire Actual Widths

Welcome to the Cyclocross Tire Actual Widths chart!

One of the things I search for the most is actual width on CX tires. We all know there are tons of variables that contribute and there’s no way to keep track of it. Donnelly’s tires are a great example. The MXP can be anywhere from 34 to 38mm wide depending on what rim width you have. Actual tire width is still important to me and many others. While the UCI 33mm rule doesn’t apply to most, the 38mm masters rule does. And there are plenty of other people who have clearance issues.

Here’s how the Cyclocross Tire Actual Widths chart works:

Tires are on the left, internal rim width on the top.

All sizes are in MM.

B2B is the actual Bead To Bead measurement. Measured while the tire is laying flat.

The two widths in the chart are New/Aged. As a tire ages, it can grow a little. This is important, as your legal tire at the start of the season might not be legal at nationals.

Measurements taken at 25psi.

Have something to add? Please email us and we’ll add it to the chart.