At 10:41 PM 28/12/2007 -0600, John Thompson wrote:
>Seamless tubing is produced by piercing a solid piece of steel with a
>mandrel, and repeated drawing through dies until the final shape and
>dimensions are achieved.
>
>Some seamed tubing, e.g. Reynolds 501, True Temper, etc, start as strips
>rolled and welded into tubes and drawn through mandrels to obliterate
>the weld seam, but AFAIK, 753/531, and most other high-end tubing was
>produced as truly seamless.
That has always been my understanding. Reynolds always made a big deal of how they did this and butted the tubes. If a cycle manufacturer was receiving "531" from Reynolds in the 1970s that appeared to be seamed, it could only be that the manufacturer had pressured them for a lower price and agreed to go easy on inspection so 501 could be substituted. With the huge volumes of tubing used by Raleigh, Reynolds couldn't afford to supply it at cost or with minimal margin. These days such demands are made routinely by big companies like GM and the suppliers either find a way to conform or lose the contract and close up shop. All the customer was looking for was the right sticker and very few actually stressed the frames to the point where it made any difference.
John Betmanis
Woodstock, Ontario
Canada