When I received what I thought was an early-60's "Mod. B" (flat crown) Cinelli from a distinguished member in the UK a few years ago, it had a loooong OT post in it that is 25.6 (1.007" OD) and figured the proper post for the bike (with plans to ream for distortion) should be a 25.8 (1.016" OD.) 4 1/2 thousandths per side isn't a lot of material, and theres probably less material than that after 40-50 years of squeezing to get that bore cylindrical again. Anyways, after reading the recent posts about 26.2 (1.031 OD) being "proper" for this vintage, I went out with my trusty Mit calipers and measured that bore several times and find that the nominal bore of the seat cluster up at the edge as well as down inside is ~1.020." I cannot imagine it to be distorted as consistently as it measures, yet it appears it should take a 25.8 post!
Heavier tube? A Riviera? Or.....??????
Submitted for discussion by the Cinelli and Columbus illuminati...
Dale Phelps,
Montagna lunga Colorado USA