How to Measure a Hardtail Mountain Bike

Most mountain bikes today are hardtails, meaning they have suspension in the front, not in the rear. This style is common among mid-level and high end bikes. They are usually made from steel, aluminum or carbon fiber, accommodate 26" or 29" tires, and have flat handle bars with trigger or grip-type shifters. The frame size is determined by the length of the seat tube. The instructions below explain how to measure a hardtail mountain bike.

Frame Diagram


Measuring Instructions

  • 1 Identify the top of the seat tube, where the seat clamp holds the seat post.
  • 2 Identify the center of the bottom bracket (it's the axle that holds the crank arms together).
  • 3 Measure the distance between the two points (C-T) - this is the length of the seat tube.
  • 4 Record your measurement in both centimeters (cm) and inches (to the nearest half-inch).
  • 5 Select your bike size from the drop-down on the right to see a rider height chart.


Hardtail Mountain Bike

Rider Charts

Once you know your bike's frame size, select it from the drop-down to see how tall riders should be to use this bike.


Center to Top (C-T) - This is the length of the seat tube, measured from the center of bottom bracket to top of the seat tube.

Metric (cm) - Road bikes are measured in centimeters.

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