Re: [CR] Re: Seatpost size for a 1960 Ideor, Columbus tubing

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From: <gpvb1@comcast.net>
To: classicrendezvous@bikelist.org
Subject: Re: [CR] Re: Seatpost size for a 1960 Ideor, Columbus tubing
Date: Mon, 31 Jan 2005 05:45:19 +0000


Date: Sun, 30 Jan 2005 14:15:37 -0800 (PST) From: Peter Jourdain <pjourdain@yahoo.com> To: Classicrendezvous@bikelist.org Cc: john jorgensen <designzero@earthlink.net> Subject: Re: [CR]Re: Seatpost size for a 1960 Ideor, Columbus tubing

Hi, John, All--

Thanks so much for the response, and for taking the trouble to check with your brother regarding his Ideor frameset. I genuinely appreciate it. It's very curious, the 26.8 number, because the seller of the frameset, an Italian bike aficionado, also told me it is was 26.8, and so I bought a Campy seatpost in that size almost immediately.

Let me tell you, after trying to force the thing into the seat tube, even heavily greased, and succeeding only in gouging up the post and (I feared) being on the verge of splitting the tubing itself, I stopped.

I wonder if the two years difference in model years between your brother's bike and mine might be enough to account for a difference in seattube diameter. The fellow who sold me the frameset also owned a '57, and his statement as to the seatpost size on mine might have based on his experience with the earlier frameset. All I know is, 26.8 into mine won't go, and even 26.2 is going to require a level of muscle I'm hesitant to apply. Hmmm....

Ideor offered the Asso in I think five different model levels, relating primarily to coponent mixes. Except for the lowest level model, which used Mannesmann tubing, they all used Columbus, including mine, the lower-mid-level Asso "Olimpic." The top "Professional" model had a Campy cotterless chainset and Sport headset, etc., the lower models had Magistroni cottered chainsets and Ideor-branded Magistroni headsets. But as I say, all tubing except for the model below mine was Columbus.

So either the diameter of the tubing changed over the course of a couple of years, or it changed model to model, or perhaps even from frame size to frame size? You say your brother's bike is a 53cm. Mine is a 64cm. Would a narrower diameter tubing make for a stiffer frame at the larger size? I would have thought the opposite. I'm delving into territory I know almost nothing about here.

I guess I have to keep the question open...

Thanks again,

Peter

Peter Jourdain Whitewater, Wisconsin

Hi Peter: Larger frames can sometimes have thicker-walled tubes, so yes the post can be a slightly smaller size on a large frame than on a small frame (e.g. 0.2 mm smaller for SP than for SL tubing). Is the seat tube I.D. for sure that small, or has the seatlug perhaps been clamped down over a too-small diameter post? I see that all the time - make sure that the ears of the lug are not too close together / crimped / smashed. I will try to check my chrome 1960s Ideor frameset (a bare 61 cm that I recently purchased from a list member and haven't yet built up) for seatpost size tomorrow. E-mail me off-list and we'll see if we can get to the bottom of this issue.....
Regards,
Greg Parker
Ann Arbor, Michigan