How to Pick the Right Size Bicycle

If you are planning a new bicycle purchase, it is wise to take a few moments and a few measurements to make sure that the bicycle you select is the proper size for the person who will be riding it. With a few materials, you will be able to measure the body frame of the bicycle rider before bicycle shopping. Once these measurements are taken, you will have the information necessary to pick a bicycle that will be comfortable and safe to ride for many miles.

Things You'll Need

  • Tape measure
  • Wall space
  • Pencil
  • Paper
  • An Assistant
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Instructions

  1. Pick the Right Size Frame

    • 1

      Stand against a wall with feet positioned naturally. It is recommended that you wear the shoes that will be worn while biking.

    • 2

      Measure the inseam length from crotch down to the floor with the tape measure. Inseam length is the measurement needed to calculate stand-over height.

    • 3

      Measure the torso length from the same inseam point up to the collarbone.

    • 4

      Stretch one arm out to the side with it parallel to the floor. Make a fist and rotate it so that the thumb is facing up. Measure from the collarbone point to the center of the fist for the arm length.

    • 5

      Analyze your bicycle choices to select the proper bicycle size for the measurements taken. Find a bicycle with a stand-over height that equals the inseam measurement with two inches subtracted for a road bike and four inches subtracted for a mountain bike.

    • 6

      Figure the proper top tube length for your measurements. Add the torso measurement to the arm measurement. Divide this sum by 2 and subtract 6. The answer is the top tube length that is the proper size for your measurement.

    Adjust the other Bicycle Parts for Your Size

    • 7

      Determine the best crank length for your body size. Measure the distance from the top of your femur to the floor when standing without shoes on. Figure 18.5% of this measurement to reach the recommended diameter of the crank for a bicycle.

    • 8

      Position the seat at a height that allows the knee to be bent slightly when at the bottom point of the pedal motion.

    • 9

      Place the seat in a position that would allow you to lift your hands from the handlebars and be able to keep your upper body in the same position without discomfort.

    • 10

      Use an adjustable stem to determine the best handlebar position for you. Many people set the handlebars so that their elbows are in an approximate 90 degree angle, but this is very individual. It also depends upon the kind of bicycling you will be engaging in.