How to Measure Bike Post?

The most accurate way to measure your bike seat post is to read the number printed on the post itself, or to use calipers to measure the diameter.

The provided YouTube video, Identifying Your Seat Post Size | Tech Tuesday #168, shows that seat post size is related to the diameter of the post. It also shows how the measurement on the screen will change depending on the angle at which you're measuring with calipers. For example, the video shows an angled caliper measurement displaying "26.05" on the screen. The key is to measure the true diameter.

Here's a breakdown of methods:

Methods to Determine Your Seat Post Size

• Check the Existing Seat Post: Look for a stamped or printed number on your current seat post. This is the most reliable method. It's usually near the bottom of the post.

• Use Calipers:

  1. Purchase Calipers: You'll need a set of digital or dial calipers for accurate measurement.
  2. Clean the Post: Wipe the seat post clean where you plan to measure.
  3. Measure the Diameter: Carefully measure the outside diameter of the seat post using the calipers. Ensure you are measuring straight across, not at an angle.
  4. Read the Measurement: The calipers will display the diameter in millimeters (mm).

• Have a Bike Shop Measure It: If you're uncomfortable doing it yourself, your local bike shop can easily measure the seat post for you.