Before ordering, you will need to know your seatpost extension and your seatpost diameter.

Seatpost Extension is determined by measuring the distance between the center of the saddle rails and the point where your seatpost enters your bike frame.

NOTE: Be sure to have your saddle adjusted to the proper riding height before taking this measurement. 

* Weight varies with tubing diameter.

Seatpost Diameter is determined by removing your current seatpost and noting the number stamped just below the minimum insertion line. If you can no longer read the number, you will need to take the seatpost to a local bike shop for sizing or have it measured using dial calipers for a precise measurement.

Thudbuster seatposts are available in numerous exact-fit sizes.

25.4, 26.8, 27.0, 27.2, 30.9, 31.6

If your bicycle frame requires a size other than one of those listed above, we can adapt either a 25.4 or a 27.2 Thudbuster to your bicycle using a machined aluminum shim. See the list below of our standard shim sizes. If you still do not find your size, contact us and we will find a solution for your bike.

25.4 - 26.0 mm
25.4 - 26.2 mm
25.4 - 26.4 mm
25.4 - 26.6 mm
25.4 - 26.8 mm
25.4 - 27.0 mm
25.4 - 27.2 mm

27.2 - 28.6 mm
27.2 - 29.0 mm
27.2 - 29.2 mm
27.2 - 29.4 mm
27.2 - 29.6 mm
27.2 - 29.8 mm
27.2 - 30.0 mm
27.2 - 30.2 mm
27.2 - 30.4 mm
27.2 - 30.6 mm
27.2 - 30.8 mm
27.2 - 30.9 mm
27.2 - 31.4 mm
27.2 - 31.6 mm
27.2 - 31.8 mm