Road Cycling - Not exactly sure on my seapost diameter...

Hi, i THINK my seatpost diameter is 27.0

But, it's hard to find seatposts this size. Most seem to be 27.2.
Would i be able to fit a 27.2 into an opening meant for 27.0?

No. You can't put a larger post in a smaller seattube.

The size of the post should be stamped near the bottom. If not, have it measured with a metric caliper to get the correct size. 27.0 seatposts are available, but it may be a special order from your LBS.

I bought a seat post which is supposed to be 27.2 but it is actually closer to 27.

Go to your LBS and ask them to measure it.

If you are sure you need 27mm, try this link: http://catalog.bicycleblowout.com/site/intro.cfm?PageID=37&Category=1453

While we are on the subject.My Bike takes a 27.2 seat post.I bought a in line seat post.It felt like a different fit.It was marked up with 27.2.but when i checked it with a micrometer it was 26.85. I did tighten the clamp so that it did not move in the frame.
The question is will this damage the frame(I tightened up the clamp with out thinking and only thought to measure the post as a after thought)

Originally posted by phat bahsturd
Would i be able to fit a 27.2 into an opening meant for 27.0?
In some instances, YES. I had a 27.2 post in my 27.0 Ibis Scorcher, a little tight sliding in and out, but no problem.