How do I measure my seatpost?Updated a month ago

To determine the correct seatpost size for your bike, you need two key measurements: the seatpost diameter and the seatpost length. This guide will show you exactly how to obtain both measurements so you can select the correct size.

How to measure seatpost diameter: 

Seatpost diameter is almost always printed on the seatpost itself. You may need to remove the seatpost to find this measurement, but it's the easiest and quickest way to find the seatpost diameter. Common diameters include 27.2mm, 30.9mm and 31.6mm. 

If your seatpost diameter isn't printed on your seatpost, the most accurate and common way to measure seatpost diameter is by using a digital or vernier caliper.

The goal is to measure the outer diameter (OD) of the part of the seatpost that slides into the bike's frame. This measurement should be precise to the nearest tenth of a millimeter (e.g., 27.2 mm, 30.9 mm, or 31.6 mm).

How to measure seatpost length:

To determine the length you will need, measure your current seatpost from the seat collar to rails and compare column B in the chart below! So as an example, if your 30.9mm seatpost measures 275mm from Collar to Rails, you would need to purchase the 400mm length post: