How to Calculate Stack Height

Stack and reach are required to determine the size of a bicycle frame appropriate for a rider's body when taking into account the length of one's arms, torso and legs. Together, stack and reach equal frame size for bicycle models such as road bikes, mountain bikes, BMX, townies and cruisers. The frame's stack height must be calculated to determine the frame's dimensions. Stack height is the measured vertical distance from the center of the radius of the bottom bracket to the center of the radius of the head tube.

Things You'll Need

  • Millimeter tape measure
  • Bike stand
  • 4-inch bubble level
  • Masking tape
  • Paper
  • Pencil
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Instructions

    • 1
      The center of a wheel nut constitutes the center of the wheel's radius.

      Secure the bicycle in the bike stand. Measure the distance in millimeters of the center of the radius of each wheel from the floor. Adjust the bicycle stand until the center of both wheels are an equal distance from the floor.

    • 2
      The seat tube is shown behind the rider's leg running vertically up to the seat stem and seat.

      Place the bubble level vertically on the right or left side of the seat tube. Adjust the bike stand until the bubble level indicates the bicycle is resting precisely vertical in the bike stand.

    • 3
      A pedal crank rotates around the center of the radius of the bottom bracket.

      Measure and record the distance from the center of the radius of the bottom bracket to the floor. Place the bubble level on the side of the tape and ensure the tape is running precisely vertical from the center of the radius of the bottom bracket to the floor.

    • 4

      Measure and record the distance from the center of the radius of the head tube to the floor. Place the bubble level on the side of the tape and be certain the tape is vertical from the center of the radius of the head tube to the floor.

    • 5

      Subtract the distance from the center of the bottom bracket to the floor from the distance of the center of the radius of the head tube to the floor to determine the stack height.