You are reading a single comment by @chris_gee and its replies.
Click here to read the full conversation.
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
@chris_gee
The sizes go in .2 mm increments, so next smallest would be 27.0, 26.8, 26.6 (not so usual but 531 for large frames used that size)...etc etc. If 27 is too tight and 26.8 too loose then you would ream the seat tube slightly to fit a 27.0. Always get a new post if you can, as a used post could have been scratched then polished, (which may have marginally reduced the diameter ) and not a 'true' size tolerance wise.