OK Pebc.. I think you are getting confused between seatpost and the QRs. The diameter of the seatpost is 33.9/34.0. There is more stress on the Swift seatpost than most bikes because of it's length and because of it's double function. The quick releases (qr's) that come with the swift are very inexpensive models (and low quality in my opinion). As long as you get better quality qr's that fit properly you will be fine. ps---I owned and managed a bicycle shop for 30+ years... I have replaced a lot of qr's in my career on different bikes.