If it needs a 27.0, a 26.8 may not work too well. My experience was with buying a new Zeus 2000 post for a bike that needed 27.2. The Zeus box was marked 27.2, but the post kept slipping. Closer inspection showed the post itself was marked just 27, so the box was mismarked. Even though only 0.2 mm too small, I could not (or dared not) tighten the binder enough to stop the post slipping, so I bought another post, eventually finding a use for the Zeus on another frame. There are definely quality 27.0 posts still available, including American Classic, but most are too modern-looking for a 60's Legnano. A more correct-looking solution might be a straight post, as these can stiil be found in a variety of sizes, and a chromed steel seat clamp, which I'd think some here would have. If you must have Campy, 27.0 do exist. Maybe someone on the list has one for sale or trade, at least it doesn't hurt to ask. There is definitely enough material on a Campy post to turn it down 0.2 or more. Exxon Graftek and some other frames with odd tube sizes used turned down Campy posts. But these were done on a lathe. I don't know how cosmetically acceptable the results from cruder methods like sandpaper might be.
Regards,
Jerry Moos Houston, TX
john ames <anthrologic@gmail.com> wrote: Thank you all for your thoughtful replies. I did work the 27.2 (Campy) post into the tube and lug about 3" without too much sweat, before backing out. So I think 27.0 is probably the closest. Is there a standard tolerance for seatpost to tube? Is it 0.05 as suggested or should I go with a 0.2 ? Given the design of the seatpost lug (the nut is inside the main tubeset) I really dont want to risk overtightening. I am thinking of just shaving my 27.2 down because: 1. There seems to be plenty of metal on the Nuevo Record post. 2. I dont know if there are 27.0 Campy NR posts available. 3. My wife might do me harm if I keep spending money on this restoration. If this seems stupid to you, Im sure you'll let me know!
Again, thanks for the help.
John Ames
silver spring