Re: [CR]Mechanical question about Cinelli 1-R stem (Josh Berger)

(Example: Events:Cirque du Cyclisme:2004)

From: "Jon Schaer" <jschaer@columbus.rr.com>
To: <Cino1947@aol.com>, <classicrendezvous@bikelist.org>
References: <15f.27b5c6cd.2cd59f59@aol.com>
Subject: Re: [CR]Mechanical question about Cinelli 1-R stem (Josh Berger)
Date: Sat, 1 Nov 2003 19:53:19 -0500


----- Original Message ----- From: <Cino1947@aol.com>
> The handlebar is a 66-42, OS crest logo- almost impossible to find, and I'd
> like to rescue it, hoping to use it with a 1-A stem.Undoing the bolt completely
> barely allows the handlebar to move.
>

I'm interpreting this to mean that the bar is held captive in the stem, having been deformed enough by the internal wedge. It's hard to suggest how much tactile-feel effort to use in your attempt to remove it. Definitely try to lubricate the area first. Maybe simple oil would work, or heat some paraffin wax thin enough to seep in (don't do this unless you know how to heat it safely). Heating the area might possibly help, but I doubt it. But use air, not flame. An industrial heat gun gets plenty hot enough. But this technique helps parts that are seized by pressure or corrosion. I doubt enough space will be created to allow misshapen parts to clear.

If you decide to cut, a Dremel is sufficient. There are some great cutting wheels available, and various sizes allow for more delicate work. I'd guess that if you cut from above and behind the bar, into the chamber of the wedge, you can avoid potential bar damage, and once you through, a screwdriver will pry it open enough for bar removal.

After it's out, you might have trouble getting it into another stem, though. Framebuilders use blocks to work out dents and dimples in tubes, but getting something designed for a 26.4mm tube may be the crutch (maybe 26.8mm tube blocks will be close enough).

As a generality, messing around with the clamp area of a bar isn't a great idea. That's where most of the stress and fatigue is concentrated anyway. Even though those are pretty stout bars, if the deformation is severe enough, "squishing" it back to round might just weaken it past the margin of safety.

Jon Schaer
Columbus, OH