Re: [CR]campagnolo no-stamp brakes detail

(Example: Framebuilders:Masi)

Date: Wed, 19 Jul 2006 06:15:17 -0500
From: "John Thompson" <JohnThompson@new.rr.com>
Organization: The Crimson Permanent Assurance
To: Classic Rendezvous <classicrendezvous@bikelist.org>
Subject: Re: [CR]campagnolo no-stamp brakes detail
References: <20060712030632.81653.qmail@web50406.mail.yahoo.com>
In-Reply-To: <20060712030632.81653.qmail@web50406.mail.yahoo.com>


Tom Dalton wrote:
> Where did this notion of the non-existance of 753 blades come from?
> One listmember recently noted that his frame included a fork decal
> marked "753 fork blades" or some such. Wouldn't such a sticker be a
> little odd of no such blade existed?

No. They exist. Came in every box, in fact. I still have an uncut 753 tubeset, complete with fork blades. :-)
> As I recall a lot of fuss was made about the special 753 frok blades,
> because they were only available pre-raked from Reynolds. Only
> certain offsets were available. My understanding was that the blades
> were raked, then heat treated, and couldn't be altered after that.

Yup.
> You can't chrome it (though it can actually be chromed w/o problem
> according to folks who would know).

Reynolds recommended against chroming. If you chromed it, you did so at your own risk.
> "Silver solder only" though this assertion has been questioned on
> this list, as has the relevance of the term "silver solder"

Using brass requires higher temperature and thereby negates the advantage of the heat treatment. Use brass and all you have is a light-gauge 531 set.
> It can't be cold set (either after brazing or crash damage). I
> assume this is more or less true, but I'm not a frame builder, not
> even close.

Yup. We tried it once, just for laughs, on a damaged team frame. The down tube buckled (at the shift lever braze-ons) before it would take a set.
> You need to pass "the 753 test." This, I assume, arose from the
> previous two issues. That is, bad brazing (overheating) was a
> bigger issue because of the heat treatment, and bad alignment could
> not be corrected by cold setting. Also, it was said that the
> tolerances on the joints needed to be tight b/s silver doesn't fill
> big gaps.

The test was just for brazing quality. You'd braze a few lugs to tubes and send them to Reynolds for destructive testing.

--

-John Thompson (john@os2.dhs.org)
Appleton WI USA