Originally Posted by techman

I need to replace the seat post of an older bike that I'm restoring.
The seat post has engraved markings, in which one of the lines of text implies the diameter measurement. It starts with an 0, O or circle but with an angled line through the 0,O or circle. Then it reads 25 and then there is a space, then it reads 40.
My assumption is that this is a 25.4 mm post, and when I measure with a ruler it looks to be true (very close to 1"). Unfortunately I don't have a caliper tool to verify this.
I would appreciate some feedback regarding my assumptions.
Thanks