How to Measure for a Mountain Bike

You can spend a fortune on a mountain bike with top-of-the-line components, but if it's the wrong size, you won't enjoy a safe, comfortable ride. Measuring for a bike involves fairly basic steps, but be sure to take those steps before you test-ride different models. That way, you can get a true idea of how you feel on the bikes and can make an informed purchase.

Instructions

  1. How to Measure for a Mountain Bike

    • 1

      Find a bike store staff member who seems knowledgeable and patient---and who rides mountain bikes. Ask the person to help you measure and to offer you tips. If you feel rushed or neglected, go on to the next bike shop.

    • 2

      Select a mountain bike you want to test-ride. Straddle it, and make sure there are about 2 to 4 inches of space between your crotch and the top tube. For commuting, you only need about 2 inches of clearance; wilder riders need about 4 inches.

    • 3

      Determine whether you have a comfortable reach from the seat to the handlebars. This is a major factor in improving handling and maintaining stability. Different size bikes can have top tubes of different lengths, so getting on the bike is the best way to measure for your needs. Although this involves personal comfort, bike shop staff should be able to guide you.

    • 4

      Adjust the seat to your level and make a test measure. When you're sitting on the seat and your foot is all the way down on the pedal, your leg should be nearly straight.

    • 5

      Take some measurements if you can't straddle and ride a bike---for example, if you're buying via the Internet. To start, measure your inseam. Stand against a wall with your bare feet shoulder width apart. Hold a ruler at your crotch and ask someone to measure from that ruler to the ground. An alternative is to stand with a book between your legs that reaches up to your crotch. Measure from the top of the book to the floor. Plug the measurement into a Web site sizing table to find your best fit. (See Resources below.)

    • 6

      To determine your ideal top tube length, measure your torso and arms. For the torso, again stand with the book between your legs. Measure from the top of the book to the indentation at the bottom of your neck. For arm length, stretch out your arm 45 degrees and make a fist. Measure from the edge of your shoulder to the middle of your fist. Add your torso and arm lengths, divide by 2 and add 6 to find your ideal top tube length. (See Resources below.)