Tripolar on most days
seatpost sizes are so close does it matter if you use the wrong one. A 26.8mm is 1.05512'' and a 27.2 is 1.07087'' that is only .01567'' differance. Is it possiable to use a 27.2 instead of a 26.8. I know that my bike is one of the two but I have read different spec's on the bike. It is a Bianchi D.I.S.S. and some of the spec's say its 26.8 and some say it is 27.2. I know the new Bianchi SASS spec's out a 27.2. If someone can tell me what it is or if I could use either one and what could happen if I use the wrong one.