How to Size a Road Bike Frame

Selecting a road bike that is the correct size and fits you properly is critical to fully enjoying biking. A bike that is too small or large for you can lead to injury, less efficient riding, less enjoyment due to it being uncomfortable and can be unsafe. A simple process of finding your measurements and matching them to the appropriate road bike can make your rides much more enjoyable and productive.

Things You'll Need

  • Tape measure in centimeters and inches
  • Book
  • Calculator
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Instructions

    • 1

      Measure your inseam, which is the inside part of your leg. Stand against the wall in your bare feet. Take a book and press it up against your pubic bone between your legs and have it touch the wall. Hold the book where it is and step away. Using the tape measure, measure from the top of the book down to the floor. Record that in both centimeters and inches. Most road bikes are measured in centimeters, but some are in inches so it is good to have both so you won't need to repeat this step.

    • 2

      Multiply the inseam measurement by .65. For example, if your inseam measurement is 90 centimeters then take 90 x .65 = 58.5. In this case you can probably round down to 58 so you would fit a 58 centimeter bike frame that measures center to center. There are two ways to measure the frame height of a road bike--center to center and center to top. If the bike you are interested in is center to top, then multiply by .67, so in this case it would be 90 x .67 = 60.3 or a 60 centimeter frame. The dealer you are purchasing the bike from will be able to tell you how the bike is measured.

    • 3

      Test ride all bikes before you purchase. Because of differences in manufacturers and bike models, one 58 centimeter bike might feel much different than another 58 centimeter bike. It is very important that a bike not only fits correctly according to the measurements but that it also feels comfortable to you.