A few months back, I picked up a beautiful Molteni Orange Lighthouse frame, with a Cinelli Bottom Bracket Shell, Campagnolo dropouts, and a Gipiemme rear brake bridge. The frame is marked with a generic, mid 80s Columbus tubing sticker, so I have no idea which model it has. (I have since mated the frame with a NOS Antonio Mondonico chrome fork, it's pretty swank)

Now it's awfully pretty to look at, but I am having trouble with figuring out this issue with my seatpost. When I purchased the frame, the former owner told me that the frame was meant for a 27.2 seatpost. Well, I came across a 3TTT 27.2 post, but I couldn't get it to go in. I took the frame to a LBS and had them size it for me, 27.1. The guy who looked at my bike insisted that the frame was meant for 27.2, but at one point, a smaller seatpost was inserted and clamped in, distorting the clamp. He recommended that I wedge in a piece of wood, and try and spread the clamp a little. Well, it spread a fair amount, but the fit is still awfully tight, I can only get the seatpost in about 1" or so.

Prior to all of this, my understanding was Columbus tubing was almost always a 27.2 for the seat tube. But I could be wrong, but I have never come across a bike with Columbus tubing and anything other than a 27.2 seat post.

Any ideas as to what my problem could be?


thanks in advance.

Keep spreading?

columbus is all over the place, alelle is 26.8, collars can change the seatpost size, etc,etc...but it could certainly be 27.0 instead of 27.2. go to the lbs and see how a 27.0 fits.