Yes, drawn from solid material. Started as very large square billets, rolled to rough size, made round, pierced, and drawn to diameter over several steps. Then butted.
I've got a 531 promo film that shows nearly the entire process, as well as some brazing action at what I think is a Raleigh plant, plus shop and race footage.
I did a pretty crummy transfer to video from 16mm. It's a pretty big file, maybe too big for you tube? It does fit on a DVD though, and there's a few copies out there. I sent some to the cirque a few years ago for the auction or for door prizes or whatever, but never heard if they got there- totally understandable considering they'd have arrived the day before or maybe the first day when everything would have been very busy. Anyone have one they can post? I watch you tube, but haven't tried posting yet.
Steve Birmingham Lowell, Massachusetts USA
From: Amir Avitzur <walawalaoxenfree@gmail.com> Subject: [CR] It seams so unbelievable To: classicrendezvous@bikelist.org Message-ID: <AANLkTinOyEzD0T1tRg6Cp-sJOZcTk98BRMUkfMMh917A@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1
Tubing drawn from solid material is considerable more expensive than tubing drawn from rolled plate that was welded and then drawn. It is, potentially stronger and tougher, but that depends on the chemical composition and type of processing (esp. heat treatments) during manufacturing.
As the bike industry was always very competitive, my guess is that "drawn from solid stock" would not have fared well.
It is possible to make a highly reliable and lightweight tube out of seamed stock. If drawn enough times and processed properly, it would take a metallurgist to discover the seams.
So, does anyone know for sure that Reynolds 531 DB tubing started out as solid stock, or are we all guessing.
Amir Avitzur R"G Israel
BTW: I drew tubes on a laboratory drawbench, a long time ago ...