Re: [CR]Alex Singer Lugs and BB

(Example: Framebuilders:Brian Baylis)

Date: Sat, 15 Oct 2005 12:40:04 -0700 (PDT)
From: "Fred Rafael Rednor" <fred_rednor@yahoo.com>
Subject: Re: [CR]Alex Singer Lugs and BB
To: Amir Avitzur <avitzur@013.net>, Classicrendezvous <classicrendezvous@bikelist.org>
In-Reply-To: <JJEEKLDDELHGFDGDBELBAEBHCHAA.avitzur@013.net.il>


Amir,
    The technique you describe would have made tremendous sense but Schwinn chose another method for making the head-tubes and BB shells for their heavier frames:
       http://www.sheldonbrown.com/varsity.html For some reason, they decided to use their own, nearly proprietary technique, despite the increased expense.
      Fred Rednor - Arlington, Virginia (USA)


--- Amir Avitzur wrote:


>
>
> Another way of making joints in tubes is to place a tube in a
> "T" shaped
> die, plug the ends, and pump fluid into the pipe under high
> pressure until a
> bubble forms in the T-opening.
>
> This is a standard manufacturing method in plumbing tube
> industry.
> The results are much stronger than a welded joint, but
> tooling costs are
> high.
>
> Schwinn may have used this method in their heyday.
>
> Amir Avitzur
> Ramat-Gan, Israel

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