How to Determine Bicycle Tire Size

How to Determine Bicycle Tire Size
Determining a bicycle tire size is usually a simple matter of checking what the tire itself says, but there are plenty of reasons why this might not be possible. In such cases, taking a measurement to determine the size is almost as easy and requires only a few minutes.


Difficulty: Easy

Things You’ll Need:
  • Tape measure Bike tire pressure gauge (optional)
  • Tape measure
  • Bike tire pressure gauge (optional)
Step 1
Look along the outside of the tire wall. The tire size and recommended inflation pressure usually are stamped into the rubber there. If you can find this and it hasn't been obscured by damage or wear, skip the remaining steps.
Step 2
Put the bicycle in a stable position. You can put it on a stand, drop the kickstand or lean it against a wall. Just make sure it won't fall on you while you are working.
Step 3
Check the tire's inflation. Pinch the tire with your thumb or use a pressure gauge. The latter will be helpful only if you know the recommended inflation pressure. If the tire is flat or almost flat, inflate it. Tire measurements are divided by increments of 2 or 4 inches, so the only way inflation will distort the measurement is if the tire is empty or almost so.
Step 4
Measure the tire. Place the tab or end of your tape measure under the bottom of the tire and extend it to the top of the tire. The tire size is the diameter of the tire from its outside edges. Slightly improper inflation can affect the measure, but not enough to prevent you from taking a measurement that can be rounded off. For example, a 23.66-inch measurement is obviously a 24-inch tire, and not a 20-inch tire overinflated to the point of exploding.
Step 5
Determine the width of the tire using the tape measure. This is usually unnecessary, but sometimes that figure is needed for specialty tires with unusual sizes.

Tips & Warnings

It is common for off-road tires, often found on mountain bikes, to have lower recommended air pressures than road tires. Do not mistake that for an underinflated tire.

Article Written By Edwin Thomas

Edwin Thomas has been writing since 1997. His work has appeared in various online publications, including The Black Table, Proboxing-Fans and others. A travel blogger, editor and writer, Thomas has traveled from Argentina to Vietnam in pursuit of stories. He holds a Master of Arts in international affairs from American University.

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