How to Measure a Road Bike Frame


Cycling with your seat too low, your seat too high, handlebars too far back or too far forward put the body in an incorrect position and negatively impact bio-mechanics. Incorrect body position hurts performance and increases the chance of injury. But spending time getting all these components adjusted correctly doesn’t matter if you’re not on the correct size road bicycle frame to begin. Get on the right size frame and cycle your best while staying healthy.

Step 1

Locate the crank shaft. This is the axle that connects the pedals to each other. It runs through the cylindrically shaped bottom bracket.

Step 2

Locate the top of the seat tube. The seat tube runs up from the bottom bracket. The top is where the seat post inserts into the frame–attaching the seat.

Step 3

Measure from the center of the crankshaft–this is also the middle of the bottom bracket–to the top of the seat tube. Do not measure the seat post, only to the top of the bike frame.

Tips and Warnings

  • Bike frames often have their frame size labeled on the top tube. Check for this information prior to measuring to save yourself some time.
    If the bike you are considering purchasing is measured in centimeters, you can convert to inches multiplying by 2.54.
  • Proper road bicycle fit takes more than just a frame measurement. There are other factors such as leg length that contribute to achieving the best possible fit.
    Once you have the correct frame, then you will need to adjust your other components to the correct position for your body.

About this Author

Aaron Jacobsen specializes in writing about health, fitness and mental performance topics for various websites. He holds a master’s degree in kinesiology and is a former faculty member at San Jose University.