re: [CR]Pulley Cage Preload on Early Campy Gran Sport

(Example: Production Builders:Tonard)

Date: Fri, 13 Jan 2006 20:34:10 -0500
From: "Harvey M Sachs" <sachshm@cox.net>
To: rg500g@yahoo.com, Classic Rendezvous <classicrendezvous@bikelist.org>
Subject: re: [CR]Pulley Cage Preload on Early Campy Gran Sport


The Gran Sport I have has a preload detent or stop screw. Looking straight at the lower pivot, the screw is at about 8:00. Conventional slotted top end; botton end has a couple of mm. threadless, reduced diameter. Oddly, the cage plate (the piece that holds the pulleys) is symmetrical, without obvious difference between the end for the top pulley and that for the bottom one. Of course, this changed on the Record model.

harvey sachs mcLean va

scott Baxter wrote:

I have an early Campagnolo Gran Sport rear derailleur in hand. No obvious dating, but the body is bronze. Unlike the '74 NR rear derailleur I have, there is no stop on the pulley cage to hold the cage spring under any tension. What I see instead is an interesting screw on the left side of the lower pivot body that seems to go to nowhere.

Is the pulley cage of the Gran Sport rear derailleur by design not tension preloaded, or is that screw a stop screw that seems to break off in every picture I've seen of this derailleur? I have a funny feeling the stop screw breaks off frequently, for part # 99 in the Gran Sport exploded view in Catalog 14 shows a longer screw than is in the derailleur, and its name is "vite regolazione cambio", whatever that means.

Scott Baxter
St. Louis, MO