Re: [CR] modifying old bike parts

(Example: Framebuilding:Tubing)

Date: Fri, 3 Jul 2009 13:06:37 -0500
From: Eric Burns <theej@mchsi.com>
To: Brian Van Baush <bvanbaush@ameritech.net>
References: <623670.49677.qm@web83006.mail.mud.yahoo.com>
In-Reply-To: <623670.49677.qm@web83006.mail.mud.yahoo.com>
Cc: classicrendezvous@bikelist.org
Subject: Re: [CR] modifying old bike parts


Brian Van Baush wrote:
> I'd like to caution against modifying old parts to fit your old bike frame.
> If you machine a seatpost, brakes, stems, etc your removing material and
> possibly putting yourself in an unsafe postion if the part fails in use. The
> same caution applies to any frame with a dimple at the down tube, a sign of
> the frame being in an accident.
>
> Just my two cents, have a safe weekend.
>
> Brian Anacortes, WA USA
>

Brian,

I posted about turning down a 25.4mm post to 24.5mm.

.9mm equals .036 or .018 per side, a difference that could be handled with sandpaper if one was patient enough.

If 18 thousands of an inch makes any appreciable difference in the strength of a seatpost, then that seatpost is unsafe to begin with.

You don't really think that the manufacturers really use a different billet or casting for each size do you?

Your caution might have some value in a paranoid, legal sense, but even that should have little application to a 50+ year old bicycle.

I'll have a wonderful, fun-filled weekend, while you are being safe <g>

Rick Burns

Streator, IL usa