Seatpost is 27.2 diameter. Shims available for 28.6, 29.2, 29.4, 29.6, 29.8, 30.0, 30.2, 30.4, 30.8, 30.9 common, 31.6 common, 31.8, 34.9 We also make a 26.8 and 27.0 mm post.

Your seapost diameter can usually be found on the lower portion of the Seatpost.