A Common Sense Guide to Bicycles

How to Measure a Mixte Bike

A mixte bike frame, common in older bikes, is unique because there are two top tubes that run from the head tube down to the rear axle making the frame extra sturdy. The step-thru design also makes the bike easier to get on and off than other frame styles. The frame size is determined by the length of the seat tube, in centimeters. The instructions below explain how to measure a mixte road bike.

Mixte bike

Mixte Road 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.

Frame Diagram

Mixte bike frame with seat tube measurement highlighted

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.