Re: [CR]Re: frame longevity vs. stiffness

(Example: Framebuilding:Paint)

From: <DAVIDTESCH@aol.com>
Date: Mon, 1 Jul 2002 18:57:42 EDT
Subject: Re: [CR]Re: frame longevity vs. stiffness
To: GPVB1@cs.com, classicrendezvous@bikelist.org


In a message dated 7/1/02 3:38:45 PM Pacific Daylight Time, GPVB1@cs.com writes:


>
> > experience. A frame with minimal yield strength on the table, has soft
> > joints
> > and doesn't feel as stiff or as lively as a frame with a lot of yield

Actually those were Steve's observations, Yes a dead frame on the table is a dead frame on the road. But remember the table gives you tremendous advantage to moving the frame, that you would never have riding it. GPVB1 made an observation about setting, but an extreme one. If you "buckle" a tube trying to set it, then you have started with something that is off a country mile. I always kept my mains at +-.005 in all tests. Once you become accustomed to doing that, it is not difficult to maintain +-.5MM as was, and probably still is industry standard. Lot of myth involved with coldsetting, as long as a frame is not too far out, it is no problem. Remember that during brazing, the metal shrinks anyway. The term "Yield" is an extreme one by my definition, as yielding is failure, like a kink, or a crack. You have the elastic range, and the plastic range, then you have yield. Reasonable setting is nothing more than very slight plastic deformation. An extreme example would be 753, lots of elasticity, loads of it. You could deflect a 753 tube till it touches the table, and have it spring back within a couple thou. If you built a crooked frame out of 753, you have built a crooked frame, period.
Dave Tesch
Milwaukee