Mike Short wrote:
> Hello All,
>
> I have a 1972 Carlton Professional which I have not ridden for a while as it
> is a little too big. My dad bought it new back in the 70s and because of
> sentimental reasons I cannot sell it. So today I decided to repack the
> bottom bracket and as I am accustomed, stuck my finger up the tubes and to
> my surprise found that the frame was pinned. I thought that the Raleigh Pros
> and the Carlton Pros were mass produced (albeit in Worksop) and this
> building technique would not have been employed. Any ideas? Serial # is: A
> 55 65
>
> Mike Short,
> Austin Texas,
> USA.
>
>
According to The Custom Bicycle by Michael J. Kolin and Denise M. de la
Rosa (1979), admittedly later than the subject bicycle.
"At the Worksop factory, only the track bicycles and the custom bicycles are individually brazed on an open hearth. All the other bicycles are ring-brazed on a specially designed machine."
"The tubes for the regular production bicycles are not pinned before the brazing operation; they are coppered (a quick tack-brazing operation using copper instead of brass) to insure proper alignment. Copper is used because it melts at a higher temperature than brass. When the frame is ring-brazed with brass, the tubes will stay in place since the brass will flow before the copper reaches its melting point"
Perhaps the production techniques changed or particular bicycle is a custom.
Marcus Coles London, Ontario, Canada.
PS. The quotes were from a .pdf copy of the book posted on the www, but I do actually own a copy of the book.