[CR]Re: Classicrendezvous Digest, Vol 6, Issue 123

(Example: Framebuilders:Jack Taylor)

In-Reply-To: <CATFOOD1E9GQvnbEG100000061c@catfood.nt.phred.org>
References:
Date: Sun, 29 Jun 2003 14:17:31 -0700
To: classicrendezvous@bikelist.org
From: "Jan Heine" <heine@mindspring.com>
Subject: [CR]Re: Classicrendezvous Digest, Vol 6, Issue 123

Cambio Corsa:

For a detailed description of how to operate the Cambio Corsa, see my article in On The Wheel. This was discussed a few weeks ago when people asked about Learco Guerra, so you'll find the exact reference in the archives. Not an original text from the old days, but I doubt they had many instructions back then anyhow...

Overall, it is cumbersome, requires some concentration, but it is not difficult to use. It does not require years of practice or detailed instructions.

To your question: the wheel goes backwards on its own, under the weight of the rider, because the dropouts are inclined. So you move the wheel forward by pedaling (softly, otherwise, it'll hit the seat tube), and backwards by coasting. The act of shifting to a bigger cog alone will move the wheel forward, so there is no need to first move the wheel, then lock the QR and shift, then adjust the chain tension (as written in one report on the system). When shifting to a smaller cog, the wheel will go back all the way. The difficult part is to get the chain just a tad slack, after you are done with the shifting itself, so it doesn't bind.

Some reports published 5-10 years ago, before these bikes started coming out of Italy and becoming somewhat commonplace, about shifting the Cambio Corsa simply are wrong, written by people who have never ridden the thing or seen it in action. (As I said above, back then, there was no info available, so the authors may be excused for their errors.)

One article stated that Bartali used one hand to shift, the other to check the chain tension at the same time. This is physically impossible (you'd need two right arms!) - Bartali probably checked the chain tension after he had shifted... although I'd think that with that much experience, he didn't need to check often. He probably knew how much pressure to apply on the pedals so that it was right.

Jan Heine, Seattle