[CR]Re: 753 vs 531


Example: Production Builders:Peugeot:PX-10LE
Date: Mon, 4 Jul 2005 19:29:06 -0700
From: "Kurt Sperry" <haxixe@gmail.com>
Cc: classicrendezvous@bikelist.org
In-Reply-To: <197.421a0be0.2ffb368d@cs.com>
References: <197.421a0be0.2ffb368d@cs.com>
Subject: [CR]Re: 753 vs 531

Thanks for the reply from a fellow frame tapper. I have convinced myself I

can tell by tapping on a bare frameset from past experience, the fundamenta l frequency seems to go up a little- maybe a 1/16th step at the transition point and the harmonics sound a little more damped in the butted sections.

I'm comfortable with that methodology for myself, but I wouldn't expect anyone else to take my conclusions seriously based only on such a subjectiv e criterion. I think a well mitered and brazed frame sounds more musical and

the ring sustains longer too. I suspect this musicality is somehow tied int o the singularly wonderful ride of a fine steel frame, but I've nothing to back it up. Tapping Al or, god forbid, CFRP frames is universally disappointing, Ti seems a little better, but cannot match steel. In my humble opinion of course! Kurt Sperry Bellingham WA

On 7/4/05, Carb7008@cs.com <Carb7008@cs.com> wrote:
>
> Kurt, IMO, my answer to your question as to whether there is a definitive
> way of determining plain gauge from butted is yes and no (how's that for
> definitive!). Almost daily I tap (w/fingernails) frame tubes on several o f
> my unbuilt frames just to hear them ring (I'm strange that way). There is a
> definite sudden difference in timbre or tone (unsure of the difference) a s
> the tap goes over a butted area. This sound is different than the gradual
> change in tone one hears as the tap appoaches the end of tube of both but ted
> and plain gauge tubes.
>
> I say no in regards to heavy gauge tubing or when brake cables etc are
> attached to tube. HG tubing is so thick it doesn't have much of a ring (a nd
> similar riding quality IMO) and butting is doubtful in any case. Cable(s)
> attached to tube mutes the ring and makes telling the difference much har der
> if not impossible. I don't have enough experience with quad-butted or any
> other tubing schemes to be able to tell.
>
> I seem to remember others saying this method is unreliable and perhaps it
> is. However, I hear the difference when I play my musical frames!
>
> Jack Romans
> Sacramento, Calif

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