Date: Wed, 11 Jan 2006 09:40:45 -0500 From: "Tom Sanders" <tsan7759142@sbcglobal.net> To: <classicrendezvous@bikelist.org> Subject: [CR] Stress risers and Pantographing
I have been told that on the prototype C Record cranks there was an engraved or Pantographed logo that left stress risers in the arm and crank failures resulted so the logo was subsequently moved and laser etching used instead. My question is...Does Pantographing of parts typically leave such risers and why or why not? I certainly have not heard of any great amount of failures among Pantographed parts. Tom Sanders Lansing, Mi
Tom: On extremely rare occasions, a vintage Record crankarm would fail right through the stamped shield logo near the spider. Campagnolo initially kept the stamped logo when the arms were redesigned with the "spider bumps" and without flutes in about 1984, following the introduction of the 50th Anniversary arms. The earliest "non-fluted" Record arms still have the stamped logo. Fairly soon after that, the stamped logo was replaced by the laser-etched logo, Company-wide. C-Record was already in production, so some of the very earliest C-Rec parts have stamped logos. Those are generally the ones that go for crazy prices on eBay right now. Campagnolo gradually switched everything over to laser-etched logos in about 1985 or so. Overzealous pantographing can certainly lead to catastrophic failures, no question. When you remove material (think brake levers, especially), you have fundamentally changed the part. You don't hear about the failures, because the total amount of pantographed parts is statistically insignificant compared to the total population of whatevers. I've seen busted "drillium" NR rear derailleurs for sale on eBay.... Greg Parker Dexter, Michigan http://www.bicycleclassics.com