The published specs for my 2018 Gepida Alboin all say the seatpost is 27.2 mm, and this requires a 28.6 clamp. I ordered a clamp (replacing the quick-release) and it is too small. The clamp fits perfectly on the smaller seat post, but I'd have to spread it apart to force it onto the downtube. Any comments? Maybe the part itself is missized, or maybe the downtube is actually larger. I'll go down in a while to see if I can get a measurement, but this puzzles me.