RE: [CR] Bilaminated Claud - more photos now on bulgier.net

(Example: Production Builders:Cinelli)

Date: Thu, 08 Jun 2006 20:02:45 -0500
To: classicrendezvous@bikelist.org
From: "Mark Stonich" <mark@bikesmithdesign.com>
Subject: RE: [CR] Bilaminated Claud - more photos now on bulgier.net


At 6/8/2006 04:01 PM -0500, Cheung, Doland wrote:
>Is bilaminted construction the addition of brass to the outside of the lugs?

Lugs! What lugs? Seriously, what you see aren't lugs.

Those frames were what we Yanks call "Fillet Brazed" AKA Bronze Welded. But before the tubes were brazed together, and probably before they were mitered, external reinforcing sleeves were "Laminated" onto the tubes. The ends of the sleeves away from the joints looked suspiciously like elaborately carved lug spigots.

Same theory as Schwinn's internally reinforced fillets, http://sheldonbrown.com/schwinn-braze.html (Scroll down for a cutaway view) but ever so much prettier. I've used the Schwinn method on tandems. Too bad I hadn't heard of Bi-Lams back then.

It's unclear to me whether the Bi in Bi-Laminated means that there are laminations on both tubes of a joint, or just that there are 2 layers of steel. Perhaps Norris can enlighten us.

BTW It seems an ideal way to build a classy looking bike where the geometry can't be accommodated with stock lugs. Tandems, recumbents etc. Given the high strength of some of the modern bronze fillers, smaller fillets could be used, for a more "Luglike" appearance.

Mark Stonich;
Minneapolis Minnesota
http://mnhpva.org
http://bikesmithdesign.com